AC9M7M05 • Year 7 Maths

Demonstrate that the interior angle sum of a triangle in (AC9M7M05)

recognise situations, including financial contexts, that use integers; locate and represent integers on a number line and as coordinates on the Cartesian plane

Choose a learning activity. Homework, Practice and Test use the same eight-question unit bank.

60-second Quick Read

  • demonstrate that the interior angle sum of a triangle in the plane is 180° and apply this to determine the interior angle sum of other shapes and the size of unknown angles
  • Example: using concrete materials to demonstrate that the sum of the interior angles of a triangle is 180°; for example, using paper triangles and tearing to demonstrate that the…
  • Common trap: using decomposition and the angle sum of a triangle to generalise the interior angle sum of an n-sided polygon, as 180(n-2)\;=\;180n-360