A protractor is used to draw and measure angles. An angle is the amount of turn between two lines. Angles are measured in degrees with the symbol °. Angles can be labelled with 3 letters (eg DEF) to ...
The angle at the circumference in a semi-circle is 90°. Angle STU = 90° Angles in a triangle add up to 180°. The angle on a straight line is 180°. The angle VOY = 180°. The angle at the centre is ...