# Constructing triangles

**Equipment needed for constructions**

When constructing a triangle, the following equipment are required:

- A ruler with cm and mm markings
- A protractor
- A pair of compasses
- A pencil

Also note that constructions are to be drawn in pencil and the lines should not be rubbed out using a eraser.

The information required to construct a triangle is as follows:

- The length of two sides and the included angle (SAS)
- The size of two angles and a side (ASA)
- The lengths of all three sides (SSS)
- A right angle, the length of the hypotenuse and the length of one other side (RHS)

**Constructing a triangle given SAS**

SAS is an abbreviation for Side, Angle (angle between the sides) and Side.

If the lengths and angles are provided for the SAS, then a triangle can be constructed using a ruler and protractor.

**Constructing a triangle given ASA**

ASA is an abbreviation for Angle, Side (side is between Angles), Angle.

Using the information of the ASA provided, it is possible to construct a triangle using a ruler and a protractor. Note that if two angles are provided, then the third can be worked out by the fact that all angles in a triangle add up to 180°.

**Constructing a triangle given SSS**

SSS is an abbreviation for Side, Side, Side.

Using the information provided, the construction of a triangle this time would be made with the aid of a pair of compasses and a ruler.

**Constructing a triangle given RHS**

RHS is the abbreviation for Right angle, Hypotenuse (longest side in a right angle triangle) and Side.

Using the information provided, the construction of the triangle would be made with a ruler and a compass. It should be remembered that the hypotenuse is always opposite to the right angle in this scenario.