🔺 Triangle Calculators

Calculate the area of any triangle when its base and perpendicular height are known. Includes the standard triangle area formula, worked example, units and key triangle terminology.

Calculate triangle area from all three side lengths using Heron's formula. Check the triangle inequality and find the semiperimeter and area from three sides.

Calculate the area of a right triangle from its two perpendicular legs. The calculator also finds the hypotenuse using the Pythagorean theorem.

Calculate the area, height, perimeter, inradius and circumradius of an equilateral triangle from its side length.

Calculate the area and height of an isosceles triangle from its two equal sides and base. Includes triangle validity checking and a worked example.

Calculate the area of a triangle from the x and y coordinates of its three vertices using the coordinate or shoelace formula.

Calculate triangle area from its inradius and semiperimeter using the standard area relationship A = r × s.

Calculate the area of a triangle from its three side lengths and circumradius using A = abc divided by 4R.

Calculate triangle area when one side, the adjacent side and the median to the known base are given. Uses the median geometry and Pythagorean relationship.

Calculate the area and all three side lengths of a 30-60-90 special right triangle from its short leg.