Understand the kite

A convex kite has two pairs of adjacent equal sides. We use the symmetric convex form, including a rhombus as a special case. Concave arrowhead or dart shapes are outside these calculators.

Properties that make the calculations work

Its symmetry diagonal bisects the crossing diagonal at a right angle. The two segments of the symmetry diagonal need not be equal. Area is half the product of the perpendicular diagonals.

Where the model is useful

Use both diagonal lengths for area. To obtain side-based perimeter as well, give the adjacent side-pair lengths and the crossing diagonal, or give the two symmetry-diagonal segments with the crossing diagonal.

Measure the right thing

The symmetry diagonal does not usually get bisected. These tools assume a convex kite, not a dart.

Sketch the figure and mark every known measurement before choosing a calculator. A length measured along an edge is not automatically a perpendicular height. If a formula needs a radius, check that the value has not been measured across a full diameter. Write the unit beside each known quantity before entering it.

Scale and units

Multiplying every length by k multiplies any area by k². This is a useful check: doubling all dimensions cannot merely double an area. Inputs expressed in centimetres produce cm² for area; the unit selector relabels rather than converts entered numbers.

Continue learning

Wolfram MathWorld: Kite provides reference reading. Our summaries and examples are written for this portal and are not a specialist-reviewed textbook. Try a worked example or suggest a correction.