Students can practise using estimation to check the measurement of acute, obtuse and reflex angles, whilst using correct angle notation within polygons with this worksheet.

Here, two irregular pentagons are drawn with vertices labelled. For the first pentagon, pupils are given the angles to estimate and measure in an anticlockwise order using notation ∠DEA. For the second pentagon, the angles are in a random order for learners to again estimate and measure the size of each. There is one reflex angle in this pentagon too.

Why not ask your students to find the sum of the angles in each polygon, what do they notice?