For a right-angled triangle, follow these steps to calculate the length of a side, \(x\), ... The triangle is coloured blue., Find the value of 𝒙 to 1 decimal place (1 dp).

A right-angled triangle will have one angle that is 90°, which means the other two angles will have a total of 90°. A scalene triangle will have all angles of a different size. Back to top ...

Many triangles in real life are not right angled. But this does not limit the use of the equation a² + b² = c² because any triangle can be cut into two right-angled ones.

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.