The features of a right-angled triangle is as follows:
- It contains a right angle
- The longest side is called the hypotenuse
- The hypotenuse is also always opposite the right angle
- The sum of all angles in a triangle is always 180°
- Two angles which add up for 90° is called complementary angles.
The opposite and adjacent sides
The two shorter sides of a right-angled triangle have special naming terms. They are called in respect of the angle x:
- Adjacent side – the side between the angle and the right angle
- Opposite side – the side opposite the x angle
Similar right-angled triangles
Two right-angled triangles with the same acute angle will be similar regardless of the length of the sides in comparison to one another.