What is the area of a triangle with base 8 and height 5? Use the formula A = 1/2 bh.

• A. 10
• B. 20
• C. 15
• D. 25

Answer: (B)

Area of a triangle is one-half the product of its base and height. With a base of 8 and a height of 5, multiply 8 by 5 to get 40, then take half of that to get 20. This reflects the idea that a triangle is half of the rectangle that would have the same base and height. If you skip the 1/2 factor, you’d get 40, which is the area of a rectangle, not the triangle.