146 core topics
+ 31 prerequisite topics taught
as needed · approximately 44 hours of instruction
including spaced review
An adaptive diagnostic (up to
40 questions) places the student on the course's knowledge
graph — topics already known are credited, and instruction begins exactly
at the learning frontier. Every topic is taught with a worked-example
lesson and auto-graded practice; a topic is mastered at
75%+ and then maintained through spaced reviews on an
expanding schedule. A cumulative quiz follows every 6
lessons. Prerequisite gaps below the course are detected and taught rather
than skipped, so completion certifies the whole tower, not just the top.
| Adding & Subtracting Polynomials
[E] |
Combining polynomials by collecting like terms. |
| Multiplying Binomials (FOIL)
[M] |
Expanding products of binomials. |
| Factoring Out the GCF
[M] |
Undoing the distributive property. |
| Factoring Trinomials
[M] |
Reversing FOIL: finding two numbers that multiply to c and add to b. |
| Special Factoring Patterns
[M] |
Difference of squares and perfect-square trinomials. |
| Solving Quadratics by Factoring
[M] |
Zero-product property: if a·b = 0 then a = 0 or b = 0. |
| Solving x² = k
[M] |
Taking square roots of both sides — remembering ±. |
| Completing the Square
[M] |
Turning any quadratic into a perfect square plus a constant. |
| The Quadratic Formula
[H] |
x = (−b ± √(b² − 4ac)) / 2a solves any quadratic. |
| The Discriminant
[M] |
b² − 4ac tells you how many real solutions exist. |
| Vertex of a Parabola
[M] |
The turning point at x = −b/2a. |
| Graphs of Quadratics
[M] |
Intercepts and symmetry of a parabola. |
| Quadratic Models
[H] |
Projectile motion and other parabolic models. |
| Product Rule for Exponents
[E] |
Multiplying powers of the same base adds the exponents. |
| Quotient & Power Rules
[E] |
Dividing powers subtracts exponents; a power of a power multiplies them. |
| Zero & Negative Exponents
[M] |
Anything (nonzero) to the 0 power is 1; a negative exponent flips to a reciprocal. |
| Scientific Notation
[M] |
Writing very large or very small numbers as c × 10ⁿ. |
| Simplifying Radicals
[M] |
Pulling perfect-square factors out of a square root. |
| Operations with Radicals
[M] |
Adding like radicals and multiplying square roots. |
| Rational Exponents
[M] |
Fractional exponents are roots: x^(p/q) is the q-th root of x, raised to the p. |
| Radical Equations
[H] |
Isolate the radical, then square both sides. |
| Exponential Growth & Decay
[M] |
Quantities that multiply by the same factor each time step: y = a·bᵗ. |
| Compound Interest
[H] |
Money growing exponentially: A = P(1 + r)ᵗ. |
| Angle Relationships
[E] |
Vertical, complementary, and supplementary angle pairs. |
| Parallel Lines & Transversals
[E] |
Angle pairs formed when a transversal crosses parallel lines. |
| Triangle Angle Sum
[E] |
The three angles of a triangle always add to 180°. |
| The Pythagorean Theorem
[M] |
In a right triangle, a² + b² = c². |
| Distance & Midpoint
[M] |
Measuring segments in the coordinate plane. |
| Similar Triangles
[M] |
Same shape, different size: corresponding sides are proportional. |
| Perimeter & Area
[E] |
Measuring around and inside basic shapes. |
| Circles: Area & Circumference
[M] |
C = 2πr and A = πr². |
| Composite Areas
[H] |
Adding and subtracting simple shapes to measure a complicated one. |
| Volume: Prisms & Cylinders
[M] |
Volume = base area × height. |
| Volume: Cones, Pyramids & Spheres
[M] |
Pointed solids hold one third of the matching prism; spheres use 4/3 πr³. |
| Surface Area
[M] |
The total area of all the faces of a solid. |
| Special Right Triangles
[H] |
The 45-45-90 and 30-60-90 side ratios. |
| Arc Length & Sector Area
[H] |
A central angle takes the same fraction of the circumference and the area. |
| The Triangle Inequality
[M] |
Any two sides together must outreach the third. |
| Isosceles & Equilateral Triangles
[M] |
Equal sides sit opposite equal angles. |
| The Exterior Angle Theorem
[M] |
An exterior angle equals the two far-away interior angles combined. |
| Congruence Criteria (SSS · SAS · ASA · AAS)
[M] |
Which marked parts force two triangles to match exactly. |
| Using Congruence (CPCTC)
[M] |
Once triangles are congruent, every matching part is equal. |
| The Midsegment Theorem
[M] |
The segment joining two midpoints is half the far side. |
| Parallelogram Properties
[M] |
Opposite sides equal, consecutive angles supplementary, diagonals bisect. |
| Special Quadrilaterals
[M] |
Rhombus, rectangle, square, trapezoid — by their defining properties. |
| The Inscribed Angle Theorem
[M] |
An inscribed angle is half the central angle on the same arc. |
| Tangent Lines to Circles
[M] |
A tangent meets its radius at a right angle. |
| Intersecting Chords
[M] |
Crossing chords cut each other into equal products. |
| Coordinate Geometry Proofs
[M] |
Prove geometric facts with slopes, distances, and midpoints. |
| Hypotenuse, Opposite & Adjacent
[E] |
Name the three sides of a right triangle relative to a chosen angle. |
| The Sine Ratio
[E] |
Sine is opposite over hypotenuse — read it straight off the triangle. |
| The Cosine Ratio
[E] |
Cosine is adjacent over hypotenuse — the leg that touches the angle. |
| The Tangent Ratio
[E] |
Tangent is opposite over adjacent — the only ratio with no hypotenuse. |
| Choosing the Right Ratio
[M] |
Match the two sides in play to sine, cosine, or tangent. |
| Pythagoras, Then the Ratio
[M] |
When only two sides are given, the Pythagorean theorem supplies the third. |
| Finding a Side from a Given Ratio
[M] |
Multiply the known side by the given ratio to reach the unknown one. |
| When the Unknown Is on the Bottom
[M] |
Divide by the ratio when the unknown side sits in the denominator. |
| Exact Values: the 45-45-90 Triangle
[M] |
Half a square: legs equal, hypotenuse √2 times a leg. |
| Exact Values: 30° and 60°
[M] |
Half an equilateral triangle gives every 30° and 60° value exactly. |
| Sides of the 30-60-90 Triangle
[M] |
Short leg x, long leg x√3, hypotenuse 2x — always in that pattern. |
| Angle of Elevation Problems
[H] |
Ground distance, height, and line of sight form a right triangle. |
| Cofunctions: sin x = cos (90 − x)
[M] |
Complementary angles trade sine and cosine — same triangle, other corner. |
| Translations by a Vector
[E] |
Slide every point the same amount: add the vector to the coordinates. |
| Finding the Translation
[E] |
Image minus preimage recovers the vector; subtract it to go back. |
| Reflections over the Axes
[E] |
The mirror line's own coordinate stays; the other flips sign. |
| Reflections over y = x
[E] |
Over y = x the coordinates swap; over y = −x they swap and negate. |
| Rotations of 90° about the Origin
[M] |
Quarter turns swap the coordinates and flip one sign. |
| Rotations of 180° and 270°
[M] |
A half turn negates both coordinates; 270° is a quarter turn the other way. |
| Identifying a Transformation
[M] |
Read the coordinate rule off a preimage–image pair. |
| Composing Transformations
[M] |
Apply the first rule, then feed its output into the second. |
| Dilations with Fractional Scale Factors
[M] |
Multiply every coordinate by the scale factor — even when it is a fraction. |
| Finding the Scale Factor
[M] |
Scale factor = image measurement divided by original measurement. |
| Rotational Symmetry
[E] |
Order n means n matching positions per full turn — every 360/n degrees. |
| Congruent or Similar?
[M] |
Rigid motions keep congruence; any leftover dilation only keeps similarity. |
| Volume of a Cylinder
[M] |
Base circle area times height. |
| Volume of a Cone
[M] |
One-third of the matching cylinder. |
| Volume of a Sphere
[M] |
Four-thirds pi r cubed. |
| Composite Solids
[H] |
Add the volumes of the parts. |
| Surface Area of a Cylinder
[M] |
Two end circles plus the wrapped-around side. |
| Scaling: Area vs Volume
[M] |
Lengths ×k, area ×k², volume ×k³. |
| Solids of Revolution
[E] |
Spin a flat shape to sweep out a solid. |
| Density: Mass, Volume & Modeling
[M] |
Mass equals density times volume. |
| Cavalieri's Principle
[M] |
Same-area slices at every level mean equal volume. |
| Modeling with Prism Volume
[M] |
Length times width times height for a box. |
| Copying a Segment
[E] |
A compass transfers a length exactly, so a copied segment matches the original. |
| Copying an Angle
[E] |
Transferring an angle's arc and chord reproduces its measure exactly. |
| Bisecting a Segment
[E] |
Equal arcs from both endpoints locate the midpoint and the perpendicular bisector. |
| Bisecting an Angle
[M] |
The angle bisector cuts an angle into two congruent halves. |
| The Perpendicular Bisector Property
[M] |
A point is equidistant from two endpoints exactly when it lies on their perpendicular bisector. |
| Constructing a Perpendicular
[M] |
Dropping or raising a perpendicular is a perpendicular-bisector construction that yields right angles. |
| Constructing a Parallel
[M] |
Copying a transversal's angle makes equal corresponding angles, forcing the lines parallel. |
| Identifying a Construction
[E] |
Read a sequence of compass-and-straightedge steps and name the construction. |
| Why Constructions Work
[M] |
The validity of each construction rests on congruent triangles and equidistance. |
| Inscribing a Regular Hexagon
[M] |
Stepping the radius around a circle marks six points — a regular hexagon of side equal to the radius. |
| Inscribing an Equilateral Triangle
[M] |
Joining every other of the six hexagon points gives an inscribed equilateral triangle. |
| Loci: Sets of Equidistant Points
[M] |
A locus is the full set of points meeting a distance condition — a bisector, a circle, or parallels. |
| Points of Concurrency
[M] |
The centroid cuts each median 2:1, and the circumcenter is equidistant from all three vertices. |
| The Midpoint of a Segment
[E] |
Average the x's and average the y's to land exactly in the middle. |
| Finding the Other Endpoint
[M] |
Reverse the midpoint formula: the midpoint is halfway, so double and back off. |
| Distance Between Two Points
[M] |
The distance is the hypotenuse of the run-and-rise right triangle. |
| Perimeter of a Polygon on the Grid
[M] |
Walk the vertices in order, measure every side, and add the lengths. |
| Area of an Axis-Aligned Rectangle
[M] |
Width times height, where each dimension is a coordinate difference. |
| Area of a Triangle from Its Vertices
[M] |
One side as base, the perpendicular distance to the opposite vertex as height. |
| Partitioning a Segment in a Ratio
[M] |
The dividing point sits m/(m+n) of the way from A toward B. |
| A Fraction of the Way Along
[M] |
Add k times the whole displacement to the starting point. |
| A Line Parallel to a Given Line
[M] |
Parallel lines share a slope; solve for the new intercept from the point. |
| A Line Perpendicular to a Given Line
[M] |
Flip and negate the slope, then fit the intercept to the point. |
| Is the Triangle Right? (Slopes)
[M] |
Two sides meet at a right angle exactly when their slopes multiply to −1. |
| Right, Acute or Obtuse (Pythagoras' Converse)
[M] |
Compare the longest side squared with the sum of the other two squares. |
| Completing a Parallelogram
[H] |
A quadrilateral is a parallelogram exactly when its diagonals share a midpoint. |
| What Fraction of the Circle?
[E] |
A central angle takes the fraction theta/360 of the whole circle. |
| Arc Length as a Piece of the Circumference
[M] |
Arc length is (theta/360) of the circumference 2*pi*r. |
| Sector Area as a Slice of the Circle
[M] |
Sector area is (theta/360) of the circle area pi*r^2. |
| From a Fraction Back to the Angle
[M] |
If an arc is a given fraction of the circle, the angle is that fraction of 360°. |
| Degrees to Radians
[M] |
A radian sweeps one radius of arc; multiply degrees by pi/180. |
| Radians to Degrees
[M] |
Multiply a radian measure by 180/pi to get degrees. |
| Arc Length with Radians: s = r*theta
[M] |
In radians the arc length is simply the radius times the angle. |
| Sector Area with Radians: A = ½r²θ
[M] |
With theta in radians a sector's area is one half r squared theta. |
| Finding the Radius from an Arc
[M] |
Invert the arc-length formula to recover the radius. |
| Inscribed & Central Angles on One Arc
[M] |
The central angle equals its arc; the inscribed angle is half of it. |
| The Tangent-Chord Angle
[M] |
A tangent-chord angle is half the arc it cuts off. |
| Central Angle from an Arc Length
[M] |
Compare the arc to the whole circumference to recover the angle. |
| Area with Two Sides and an Angle
[M] |
Two sides and the angle between them give the area directly. |
| Area Backwards: Find a Missing Side
[M] |
Turn the area formula around to recover a side length. |
| Law of Sines: Finding a Side
[M] |
Each side over the sine of its opposite angle stays constant. |
| Law of Sines: Finding an Angle
[M] |
Solve the proportion for a sine, then read off the special angle. |
| Law of Cosines: The Third Side
[H] |
c² = a² + b² − 2ab cos C reaches the side the Law of Sines can't. |
| Law of Cosines: Finding the Angle
[H] |
Three sides pin down every angle through its cosine. |
| Classifying a Triangle by Its Sides
[M] |
The sign of a² + b² − c² tells acute from right from obtuse. |
| Choosing Sines vs. Cosines
[M] |
The marked parts decide which law does the job. |
| Multi-Step Angle of Elevation
[H] |
Two sight lines to the same top pin down an unknown height. |
| Multi-Step Angle of Depression
[H] |
One height, two depression angles, and the gap between the targets. |
| Law of Sines in the Field
[M] |
Surveying and navigation triangles solved with one clean proportion. |
| SAS Area in Context
[M] |
Real plots and gardens measured from two sides and their angle. |
| Probability on a Segment
[E] |
A point on a segment lands in a region with probability length over length. |
| Length Models in Context
[M] |
Waiting times and positions are segment probabilities in disguise. |
| Probability by Area
[M] |
A dart on a region lands in a shape with probability area over area. |
| Triangular Targets
[M] |
Same ratio idea, but the favorable area is half base times height. |
| Landing Inside an Inscribed Circle
[M] |
Circle area over rectangle area keeps pi symbolic — report its coefficient. |
| Rings and Concentric Circles
[M] |
When both regions are circles, pi cancels and the answer is a clean fraction. |
| Composite and L-Shaped Regions
[M] |
Find the favorable area by adding or subtracting rectangles, then divide. |
| Population as Area Density
[M] |
Population equals people-per-area times area — density is a rate over region. |
| Comparing Population Densities
[M] |
Denser means more people per square mile, so compare population over area. |
| Choosing the Right Units
[E] |
Track units through a model: area is squared, and a probability is unitless. |
| Designing a Region to a Constraint
[M] |
Work backward from a required area to the dimension that meets it. |
| Expected Value from Geometric Probability
[H] |
Weigh each payout by its area-probability and add up the pieces. |