A right triangle has a right angle (90º) and two acute angles.

Legs or Catheti

The catheti (singular: cathetus) are the sides opposite the acute angles and are the shorter sides of the right triangle.


The hypotenuse is the side opposite the right angle, and is the largest side of the right triangle.

Area of a Right Triangle

The area of a right triangle is equivalent to half the product of its legs.


1 Pythagorean theorem


In all right triangles, the length one of the legs is a mean proportional between the hypotenuse and the projection on it.


In all right triangles, the height of the hypotenuse is a mean proportional between the two segments that it divides.

The hypotenuse of a right triangle measures 30 cm and the projection of a leg is 10.8 cm on the hypotenuse. Find the length of the other leg.

In a right triangle, the projections of the legs on the hypotenuse are 4 and 9 cm in length. Calculate the height of the triangle.

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I am passionate about travelling and currently live and work in Paris. I like to spend my time reading, gardening, running, learning languages and exploring new places.

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