Math formulas, level 2: algebra and geometry
12 formulas from middle and high school. Typed answers can use ^ for powers, sqrt for a square root and pi for π.
These are the workhorse formulas of algebra and geometry classes: right triangles, lines on a graph, the quadratic formula, and the volumes of round solids.
Tie each formula to the one it grows from. The distance formula is the Pythagorean theorem on a graph. Slope is rise over run, and the two line equations are slope rearranged. The cone is one third of a cylinder with the same base and height. Learn the parents first, then derive the children once by hand: working it out is the strongest way to encode it. Sing the quadratic formula to a tune you know.
Encode make it vivid → Space bring it back on day 1, 3, 7, 21 → Retrieve pull it from your head. From the infographic Remember It on Purpose.
Math formulas, level 2: algebra and geometry
| Formula for | Formula | Letters stand for |
|---|---|---|
| Pythagorean theorem | a² + b² = c² | a, b = the legs of a right triangle, c = the hypotenuse (longest side) |
| Distance between two points | d = √((x₂ − x₁)² + (y₂ − y₁)²) | (x₁, y₁) and (x₂, y₂) = the two points |
| Midpoint of a segment | ((x₁ + x₂)/2, (y₁ + y₂)/2) | (x₁, y₁) and (x₂, y₂) = the endpoints |
| Slope of a line | m = (y₂ − y₁) / (x₂ − x₁) | (x₁, y₁) and (x₂, y₂) = two points on the line |
| Slope-intercept form of a line | y = mx + b | m = slope, b = where the line crosses the y-axis |
| Point-slope form of a line | y − y₁ = m(x − x₁) | m = slope, (x₁, y₁) = a point on the line |
| Quadratic formula | x = (−b ± √(b² − 4ac)) / 2a | solves ax² + bx + c = 0 |
| Equation of a circle | (x − h)² + (y − k)² = r² | (h, k) = the center, r = radius |
| Volume of a cylinder | V = πr²h | r = radius, h = height |
| Volume of a cone | V = ⅓πr²h | r = radius of the base, h = height |
| Volume of a sphere | V = ⁴⁄₃πr³ | r = radius |
| Surface area of a sphere | SA = 4πr² | r = radius |
Tie each formula to the one it grows from. The distance formula is the Pythagorean theorem on a graph. Slope is rise over run, and the two line equations are slope rearranged. The cone is one third of a cylinder with the same base and height. Learn the parents first, then derive the children once by hand: working it out is the strongest way to encode it. Sing the quadratic formula to a tune you know. · teddyrookbook.com/memory/challenges/math-formulas-algebra-geometry/
Sources
- OpenStax Prealgebra 2e, Appendix C: Geometric Formulas
- OpenStax Algebra and Trigonometry 2e, Chapter 2 Key Equations
- OpenStax Intermediate Algebra 2e, 11.1 Distance and Midpoint Formulas; Circles
Checked October 30, 2026. Progress is kept on this device only (per learner). More lists: all memory challenges · memory games.