What is the area of a triangle with base 10 units and height 5 units?

• A. 25 square units
• B. 50 square units
• C. 15 square units
• D. 20 square units

Answer: (A)

Area of a triangle is half the product of its base and its height. With base ten units and height five units, multiply ten by five to get fifty, then take half of fifty, which is twenty-five. So the area is twenty-five square units. This matches the option showing twenty-five square units. The other values come from forgetting the division by two or mixing up base and height.