The area of a triangle with base b and height h is

• A. bh
• B. pi r^2
• C. 2 bh
• D. 1/2 bh

Answer: (D)

Think of how area scales with base and height. For a rectangle with the same base and height, the area is bh. A triangle that shares that same base and height sits inside half of that rectangle, so its area is half of bh. That gives bh/2 as the area formula.

So the proper expression is bh divided by 2. The other options describe different shapes: bh is the rectangle area, pi r^2 is for a circle, and 2 bh is twice the rectangle area, not a triangle’s area.