The base and the perpendicular height are at right angles to each other. The measurements used must be in the same units. For example, to work in cm a 45 mm measurement would have to be converted ...

Understanding different types of angles and that angles in a triangle sum to 180° can be helpful when classifying a triangle. Recognising line symmetry and rotational symmetry will also help.

Discusses the properties and types of triangles, explaining that a triangle is a closed figure with three sides and angles. It categorizes triangles into equilateral, isosceles, scalene, obtuse ...