1. Area Formulas and Parallelograms

2. Rectangle
Area of a rectangle = bh
b = base
h = height

3. Square
Area of a square = s2,
s = side

4. Example 1: Find the area of the following figures. 15 5 10 (–5, 4)
(2, 4)
(2, –3)
(–5, –3)
(0,0) 25 8 10 14 20

5. Example 2: a. Find the area of a square whose side is 9
b. Find the area of a square whose diagonal is 18
c. Find the side of a square whose area is 64
d. Find the perimeter of a square whose area is 100
e. Find the area of a square whose perimeter is 64

6. Example 3: Find the area of the shaded region. (Assume right angles)20 12 28 40

7. 11.2 Parallelograms Area of a Parallelogram Theorem 100
The area of a parallelogram is equal to the product of the base and the height.
A = bh
where b is the length of the base and h is the height.

8. Area of a Triangle Theorem 101
The area of a triangle is equal to one-half the product of a base and the height (or altitude) for that base.
A∆ = 1/2bh
where b is the base of the triangle and h is the altitude.

9. Example 1:
Find the total area of each figure. (In each figure the triangle is mounted on a rectangle.) 6 13 5 12 5 8

10. Example 2:
Find the base of a parallelogram of height 18 and area of 252.

11. Example 3:
Find the area of the obtuse triangle. 24
60º 5

12. Now you try!
Solve for x.