Math formulas, level 1: shapes and solids
12 formulas from elementary and middle school. Letters: l length, w width, s side, b base, h height, r radius, d diameter. Typed answers can use ^ for powers and * for times, like l*w or s^2.
Perimeter, area and volume come up everywhere: painting a wall, fencing a garden, filling a fish tank. Each formula is short, and each one makes sense once you see where it comes from.
Don't memorize these as strings of letters; rebuild them from a picture. Area of a rectangle is rows times columns of unit squares (l x w). A triangle is half a rectangle, so one-half b h. A parallelogram is a rectangle with one end slid over, so b h. Volume stacks area in layers. Draw each shape with its formula beside it (picture plus words), then recall it on a blank page and check.
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 1: shapes and solids
| Formula for | Formula | Letters stand for |
|---|---|---|
| Perimeter of a rectangle | P = 2l + 2w | l = length, w = width |
| Area of a rectangle | A = lw | l = length, w = width |
| Perimeter of a square | P = 4s | s = side |
| Area of a square | A = s² | s = side |
| Area of a triangle | A = ½bh | b = base, h = height |
| Angles of a triangle | A + B + C = 180° | A, B, C = the three angles |
| Area of a parallelogram | A = bh | b = base, h = height |
| Area of a trapezoid | A = ½h(b + B) | b and B = the two parallel sides, h = height |
| Circumference of a circle | C = 2πr | r = radius (or C = πd, with d = diameter) |
| Area of a circle | A = πr² | r = radius |
| Volume of a rectangular box | V = lwh | l = length, w = width, h = height |
| Volume of a cube | V = s³ | s = side |
Don't memorize these as strings of letters; rebuild them from a picture. Area of a rectangle is rows times columns of unit squares (l x w). A triangle is half a rectangle, so one-half b h. A parallelogram is a rectangle with one end slid over, so b h. Volume stacks area in layers. Draw each shape with its formula beside it (picture plus words), then recall it on a blank page and check. · teddyrookbook.com/memory/challenges/math-formulas-shapes/
Sources
Checked October 30, 2026. Progress is kept on this device only (per learner). More lists: all memory challenges · memory games.