Year 9 Polygons Worksheets | Printable PDFs
Year 9 Polygons worksheets for Year 9 Maths (Key Stage 3). Students aged 13–14 learn how to calculate angles in regular and irregular polygons using their knowledge of angle facts and geometric reasoning. A polygon is a 2D shape made from straight lines joined together to form a closed shape. A regular polygon has all sides and all angles equal whereas an irregular polygon has sides and/or angles that are not all equal.
Below, students investigate interior and exterior angles of polygons and explore tessellations formed by regular polygons. Angles in polygons with three sides, triangles, add up to 180 degrees, angles in polygons with four sides, quadrilaterals, add up to 360 degrees and angles with five sides, pentagons, add up to 540 degrees. Do you notice a pattern?
Sign Up to Unlock 10 Free Answers Every Month
Tessellations
Common Questions about Year 9 Polygons
What is the sum of the exterior angles of any polygon?
The exterior angles of any polygon always add up to 360°.How can you find the sum of the interior angles of a polygon?
Use the formula (n − 2) × 180°, where n is the number of sides.How are the interior and exterior angles of a regular polygon related?
Each interior angle and its corresponding exterior angle add up to 180°.
Year 9 Polygons Common Mistakes
Common Mistake 1
Using n × 180° instead of (n − 2) × 180° to find the sum of interior angles.Common Mistake 2
Assuming the exterior angles of a polygon add up to 180° instead of 360°.Common Mistake 3
Confusing interior angles with exterior angles when working with regular polygons.
Polygons Worksheets - Free Worksheets Above
Angles in Irregular Polygons
Angles in Regular Polygons
Investigating interior and exterior angles