A kite is a four-sided shape with two pairs of adjacent equal sides — think of the classic diamond-shaped toy it's named after. This calculator finds its area and perimeter from whichever pair of measurements you already have: the two diagonals, or the two distinct side lengths with the angle between them.
How the Kite Calculator works
A kite's two diagonals always intersect at a right angle, with one diagonal (the axis of symmetry) bisecting the other. That perpendicularity is what makes A = ½·d₁·d₂ exact for every kite, the same formula used for a rhombus. When you instead know the two distinct side lengths a and b and the angle θ between them, the axis of symmetry splits the kite into two congruent triangles, giving A = a·b·sinθ as an equivalent path to the same area.
Inputs and what they mean
In Diagonals mode, both diagonal lengths must be positive numbers — the calculator doesn't need to know how one diagonal splits the other, since the area formula only depends on their full lengths. In Sides + Angle mode, a and b are the lengths of the two distinct side pairs, and θ is the angle between them, entered in degrees between 0° and 180°. Unlike diagonals, knowing the sides and angle also lets the calculator compute the perimeter.
Limits and edge cases
Perimeter cannot be derived from diagonals alone: a kite's diagonals fix the overall size and the right-angle intersection, but not exactly where along the longer diagonal the two triangles meet, so many different side-length combinations can produce the same pair of diagonals. If you only know the diagonals, switch to Sides + Angle mode (or measure the sides directly) to get the perimeter. An angle of exactly 0° or 180° describes a degenerate kite with no area, so those inputs are rejected.