1. EXAMPLE 1 Finding Area and Perimeter of a Triangle Find the area and perimeter of the triangle. A = bh 1 2 P = a + b + c = (14) (12) 1 2 = 13 + 14 + 15 = 84 in. 2 = 42 in.

2. EXAMPLE 2 Finding the Area of a Triangle A = bh 1 2 = (171) (134) 1 2 = 11,457 Sailboats Find the area of the sail. Write area formula. Substitute values. Multiply. The area of the sail is 11,457 square inches. ANSWER

3. GUIDED PRACTICE for Examples 1 and 2 A triangle’s height is 9 inches and its base is 10 inches. Find its area. 1. The area of the triangle is 45 in. 2. ANSWER

4. GUIDED PRACTICE for Examples 1 and 2 A triangle’s side lengths are 4 feet, 6 feet, and 2.5 feet. Find its perimeter. 2. The perimeter of the triangle is 12.5 ft. ANSWER