Area of a Trapezoid Calculator
Calculate the area of a trapezoid using A = ½(b₁+b₂)×h. Find area from parallel base lengths and height, or from all four sides using the general trapezoid formula.
Formula & Reference
| Variable | Symbol | Formula | Units |
|---|---|---|---|
| Area of a Trapezoid Calculator | — | A = ½(b₁ + b₂) × h | square units |
Step-by-Step Examples
b₁=6, b₂=10, h=4.
- A=½(6+10)×4=½×16×4=32
A road cross-section trapezoid: b₁=8m, b₂=12m, h=3m.
- A=½(8+12)×3=½×20×3=30 m²
b₁=b₂=5, h=3.
- A=½(5+5)×3=15 = 5×3
- When b₁=b₂, trapezoid becomes rectangle
Real-World Applications
Common Mistakes to Avoid
b₁ and b₂ are the two parallel sides (bases). The legs are the non-parallel sides. Only the parallel bases go in the formula.
Height h is the perpendicular distance between the two parallel bases, NOT the length of the slanted legs.
An isosceles trapezoid has equal legs. The area formula A=½(b₁+b₂)h works for both.
Frequently Asked Questions
Related Math Calculators
Formula Explorer connections
Interpretation: This relationship connects dimensions, coordinates, angles or trigonometric ratios to a geometric measurement. Assumption: Use a consistent angle mode and length unit, identify the intended shape or coordinate system, and verify that the supplied dimensions form valid geometry.