Calculations in an isosceles triangle. This is a triangle with two sides of equal length. Enter two lengths and choose the number of decimal places. Then click Calculate. Angles are calculated and displayed in degrees, here you can convert angle units.
h = hc = √( 4 * a² - c² ) / 4
ha = hb = c * sin(β) = a * sin(γ)
p = 2 * a + c
A = h * c / 2
rc = ( 4 * h² + c² ) / ( 8 * h )
ri = c * h / ( 2 * a + c )
ma = mb = √a² + 2 * c² / 2
mc = √4 * a² - c² / 2
Lengths, height, median lines and perimeter have the same unit (e.g. meter), the area has this unit squared (e.g. square meter).
Side a and b, the legs, have the same length. The isosceles triangle is axially symmetric to the height hc.The centroid is at the intersection of the median lines. The intersections of the heights, median lines, perpendicular bisectors and bisecting lines lie all on height hc, on different locations.