Calculations in an isosceles trapezoid (or isosceles trapezium). This is a trapezoid with two opposite legs of equal length. Enter the three side lengths, choose the number of decimal places and click Calculate. Angles are calculated and displayed in degrees, here you can convert angle units.
d = √ a * b + c²
h = 1/2 * √ 4c² - ( a - b )²
m = ( a + b ) / 2
rc = c * √ ( a * b + c² ) / ( 4c² - ( a - b )² )
g = ( a - b ) / 2
p = a + b + 2 * c
A = 1/4 * √ ( a + b )² * ( a - b + 2c ) * ( b - a + 2c )
α = arccos( ( g² + c² - h² ) / ( 2 * g * c ) )
β = 180° - α
Side lengths, diagonal, height, radius and perimeter have the same unit (e.g. meter), the area has this unit squared (e.g. square meter).
The perpendicular bisectors intersect at the circumcircle center. The perpendicular bisector of the two parallel sides is the symmetry axis of the isosceles trapezoid.