Area and perimeter

Square: $A=s^2$, $P=4s$

Rectangle: $A=lw$, $P=2l+2w$

Parallelogram: $A=bh$

Triangle: $A=\frac12bh$; perimeter $=s_1+s_2+s_3$

Trapezoid: $A=\frac12(b_1+b_2)h$

Circle: $A=\pi r^2$, $C=2\pi r=\pi d$

Surface area and volume

Rectangular prism: $V=lwh$; $SA=2lw+2lh+2wh$

Right prism: $V=Bh$; $SA=ph+2B$

Cylinder: $V=\pi r^2h$; $SA=2\pi rh+2\pi r^2$

Pyramid: $V=\frac13Bh$; $SA=\frac12ps+B$

Cone: $V=\frac13\pi r^2h$; $SA=\pi rs+\pi r^2$

Sphere: $V=\frac43\pi r^3$; $SA=4\pi r^2$

$B$ is base area, $p$ is base perimeter, and $s$ is slant height. Use $\pi\approx3.14$ when directed.

Algebra and coordinate geometry

Slope: $m=\frac{y_2-y_1}{x_2-x_1}$

Slope-intercept form: $y=mx+b$

Point-slope form: $y-y_1=m(x-x_1)$

Quadratic standard form: $y=ax^2+bx+c$

Quadratic formula: $x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

Pythagorean theorem: $a^2+b^2=c^2$

Data and everyday formulas

Mean $=\frac{\text{sum of values}}{\text{number of values}}$

Median: middle value after ordering; for an even count, average the two middle values.

Simple interest: $I=Prt$

Distance: $d=rt$

Total cost = number of units × price per unit.