1. EXAMPLE 1
Use a formula to find area
Find the area of PQRS.
SOLUTION
Method 1
The base is extended to measure the height RU. So, b = 6 and h = 8.
Use PS as the base.
Method 2
Use PQ as the base. Then the height is QT. So, b =12 and h = 4.
Area = bh
=12(4)
= 48 square units.

2. Find the perimeter and area of the polygon.
GUIDED PRACTICE
for Example 1
Find the perimeter and area of the polygon. 1.
SOLUTION
A = b h 1 2
P = sum of the sides
Write formula. = 1 2 =
Substitute.
= 48 units.
= 84 units2.

3. GUIDED PRACTICE for Example 1 2. SOLUTION P = 2l + 2b A = b h
Write formula.
A = b h
P = 2(20) + 2(30)
Substitute. =
= 100 units.
= 510 units2.

4. Find the length of the base, use the Pythagorean Theorem
GUIDED PRACTICE
for Example 1 3.
SOLUTION
STEP 1
Find the length of the base, use the Pythagorean Theorem
c2 = a2 + b2
Use Pythagorean Theorem.
132 = b2
Substitute.
169 = b2
Evaluate power.
b = 12
Solve for b

5. Find Perimeter and Area
GUIDED PRACTICE
for Example 1
STEP 2
Find Perimeter and Area
A = b h 2 1
P = sum of the sides
Write formula.
A = 2 1 =
Substitute.
= 30 units.
= 30 units2.