The LessonThe area of a trapezoid is found using the formula:
In this formula, b1 and b2 are the lengths of the bases of the trapezoid and h is the height of the trapezoid. The image below shows what we mean by the lengths of the bases and the height:
How to Find the Area of a TrapezoidFinding the area of a trapezoid is easy.
QuestionWhat is the area of a trapezoid with bases of length 3 cm and 5 cm and a height of 2 cm, as shown below?
Start with the formula:
Area = ½(b1 + b2)hDon't forget: ½(b1 + b2)h = ½ × (b1 + b2) × h
Substitute the length of the bases and the height into the formula. In our example, b1 = 3, b2 = 5 and h = 3.
Area = ½ × (3 + 5) × 2 Area = ½ × (8) × 2 Area = 8 cm2Don't forget: Calculate what's in the brackets () first (using the order of operations). In our example, (3 + 5) = 8. or: ½ × a number = 0.5 × a number = a number ÷ 2.
Answer:The area of a trapezoid with bases of length 3 cm and 5 cm and a height of 2 cm is 8 cm2.
"Find the Area" Widget
- Click on the shape you're learning about.
- Click on the pad to start.
- Follow the instructions in the bottom-left corner.
- On the last click, the formula, workings, and answer will appear in the yellow box.
- Good luck!