Key Stage 2 Maths and Numeracy Northern IrelandAs well as right angles, there are also acute and obtuse angles. An acute angle is very easy to spot; it is any angle smaller than a right angle (0 ...

The text and the arcs of the angles are coloured orange. , A triangle may be described by the size of its angles, eg acute-angled, right-angled or obtuse-angled.

An obtuse triangle will have angles that are greater than 90 degrees, where an acute triangle will have angles that are less than 90 degrees.