1. Warm-Up
Find the area and perimeter of the rectangle. 25 13

2. Formulas for Triangles and Quadrilaterals
Geometry 9-1
Formulas for Triangles and Quadrilaterals

3. Main Theme

4. Parallelograms
Important: the height, h, must be perpendicular to the base
***Not on the formula chart

5. Example
Find the area of a parallelogram with b = 9 in. and h = 5 in.

6. Example
A parallelogram has an area of 44 in2. If the height of the parallelogram is 5.5 in., what is the length of the base?

7. Triangles and Trapezoids
Important: the height, h, must be perpendicular to the base

8. Example
Find the area of a trapezoid in which b1 = 8 in., b2 = 5 in., and h = 6.2 in.

9. Example
Find b2 of the trapezoid, in which A = 231 mm2.

10. Example
Find the area of the triangle.

11. Rhombus and Kite
***Not on the formula chart

12. Example
Find d2 of a kite in which d1 = 14 in. and A = 238 in2.

13. Example
Find the area of the rhombus.