Isosceles Trapezoid Calculator
Area, perimeter, legs, diagonals and base angles.
Enter your values
ⓘ Live results
Results
- Area
- 32
- Perimeter
- 24.9443
- Leg length
- 4.4721
- Diagonal
- 8.9443
- Base angle
- 63.43°
- Top angle
- 116.57°
Quick answer
An isosceles trapezoid has equal legs and equal base angles; its area is the average of the two bases times the height.
A = (a + b) ÷ 2 × h
How to use the Isosceles Trapezoid Calculator
- 1Enter both parallel base lengths.
- 2Enter the perpendicular height.
- 3Read area, legs, diagonals and angles.
Worked example
Using the values the calculator loads with:
Inputs
- Longer base a10
- Shorter base b6
- Height4
Results
- Area32
- Perimeter24.9443
- Leg length4.4721
- Diagonal8.9443
- Base angle63.43°
- Top angle116.57°
Frequently asked questions
Are the diagonals of an isosceles trapezoid equal?
Yes — equal diagonals are one of the defining properties of an isosceles trapezoid.
How do I find the leg length?
Half the base difference is the horizontal offset; the leg is the hypotenuse of that offset and the height.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.