Geometry
Shapes, area, perimeter, volume and the Pythagorean theorem
Explanation
2D Shapes — Area & Perimeter
| Shape | Area | Perimeter |
|---|---|---|
| Rectangle | lw | 2(l+w) |
| Triangle | ½bh | a+b+c |
| Circle | πr² | 2πr |
| Trapezoid | ½(b₁+b₂)h | sum of all sides |
Volume
- Rectangular prism: V = l × w × h
- Cube: V = s³
- Cylinder: V = πr²h
Volume is always in cubic units (cm³, in³, etc.).
Pythagorean Theorem
In a right triangle: a² + b² = c² where c is the hypotenuse (longest side).
Common Pythagorean triples: 3-4-5 • 5-12-13 • 8-15-17
Example: legs = 6 and 8 → c² = 36 + 64 = 100 → c = 10
Practice Questions
Test your knowledge of Geometry with a timed quiz.
Take Quiz →Topics in Mathematics Achievement