Finding the Area of Triangles TeacherTwins©2015

Warm Up c A = 1638in2 Find the area. 54.6in 2). 1). 30 in A = 7x + 21   A = 1638in2 Find the area. 54.6in 2).   1). 30 in   A = 7x + 21 2x +2 3). 4). x + 3 5 7 A = 10x + 10 4x +14 7x+21

Finding the Area of Triangles

To find the area of a triangle you multiply the base and the height and divide by 2.   h b

Example 1: Find the area of the triangle. A = (6cm)(8cm) ÷ 2 A = 24cm2 8cm 6cm

Example 2: Find the area of the triangle. A = (12in)(8in) ÷ 2 A = 48in2 8in 12in

Example 3: Find the area of the triangle. A = (6x)(4) ÷ 2 A = 24x ÷ 2 4 A = 12x 6x

Practice Find the area. 1. 2. 3. 125cm2 20cm2 300cm2 125cm2 10cm 20cm2

Closure If the area of a triangle is 36m2 and the height of the triangle is 8m, what is the base of the triangle? 9m