Maths tool · Geometry
Angles in Shapes: Find Missing Angles
triangleInterior angles = 180°
59°+?+59°=180°
Answer hidden
Use this interactive whiteboard tool to find missing interior angles in triangles, quadrilaterals and polygons. Add the known angles, then subtract from the interior angle total: 180° for a triangle or 360° for a quadrilateral. Ask pupils to explain their reasoning before revealing the answer. Choose Challenge to explore exterior angles, parallel lines and vertically opposite angles.