There are only two requirements for a right triangle. First, it has to be a shape with three sides---the "triangle" part. Second, one of the angles must be 90 degrees.

The right-angled triangle on the right has sides 6, 8, and 10 units long. The triangles are mathematically similar because one is an enlargement of the other.

In National 4 Maths Trigonometry is used to find the size of a missing side or angle in a right-angled triangle using the sine, cosine or tangent ratios. BBC Homepage. Skip to content; ...

Part of that is the way it's taught. Students are taught the "unit circle" and its relationship to trigonometry, but many fail to make the leap on how crucial circles are for trig functions.

With all due respect to Pythagoras, newly uncovered evidence suggests that his famous theorem, used to calculate the lengths of each side of a right triangle, might be 1,000 years older than him ...

The Pythagorean theorem provides an equation to calculate the longer side of a right triangle by summing the squares of the other two sides. It is often phrased as a 2 + b 2 = c 2 .

A 3,700-year old Babylonian clay tablet reveals an ancient method of constructing right-angled triangles that makes it the world’s oldest and most accurate trigonometric table.