Isosceles Trapezoid Area Calculator

This isosceles trapezoid area calculator will help you deal with these very particular trapezoids. Recall that we say that a trapezoid is isosceles if its legs have the same length. You'll experience no trouble using Omni's isosceles trapezoid area calculator, but we know that life is hard and you sometimes have to calculate with pen and paper. Don't worry — we will teach you how to find the area of an isosceles trapezoid with the help of dedicated formulas.

There are several dedicated isosceles trapezoid area formulas:

• bases a,b and height h given: A = (a + b) * h / 2

• bases a,b and leg c given: compute h via the Pythagorean Theorem (h is the square root of c² - (a-b)²/4) and A = (a + b) * h / 2

• bases a,b and angle α given: compute h as tan(α) * (a-b)² / 4 and then A = (a + b) * h / 2

• base a, leg c and angle α given: compute h as c * sin(α) and b as a - 2 * c * cos(α), then A = (a + b) * h / 2

Choose the isosceles trapezoid area formula that suits the data that is available (for notation, see the picture below). Or just use our isosceles trapezoid area calculator!

Besides the isosceles trapezoid area calculator, Omni has a vast collection of trapezoid-related tools. Make sure to take a look at:

• Trapezoid calculator
• Area of a trapezoid calculator
• Trapezoid perimeter calculator
• Trapezoid side calculator
• Trapezoid angle calculator
• Trapezoid height calculator
• Midsegment of a trapezoid
• Isosceles trapezoid calculator
• Right trapezoid calculator
• Right trapezoid area calculator
• Area of an irregular trapezoid calculator

You can compute the area of an isosceles trapezoid as:

A = 0.5 × d² × sin(φ)

where:

• A is the area of the trapezoid;
• d is the length of a diagonal; and
• φ is the angle between the diagonals.