Perimeter, Area, Volume, and Geometric Formulas

Perimeter, Area, Volume, and Geometric Formulas

The GED provides an official formula sheet. Your goal is recognizing which formula fits the geometric scenario.

2D Formulas

• Rectangle: Area = $lw$, Perimeter = $2l + 2w$
• Triangle: Area = $\frac{1}{2}bh$
• Circle: Area = $\pi r^2$, Circumference = $2\pi r = \pi d$
• Trapezoid: Area = $\frac{1}{2}h(b_1 + b_2)$

3D Volume Formulas

• Rectangular Prism: $V = lwh$
• Cylinder: $V = \pi r^2 h$
• Cone: $V = \frac{1}{3}\pi r^2 h$
• Sphere: $V = \frac{4}{3}\pi r^3$

Pythagorean Theorem

For any right triangle with legs $a, b$ and hypotenuse $c$: $$a^2 + b^2 = c^2$$