Know that the angles on a straight line sum to 180 degrees and use this to solve problems

I know that the angles on a straight line sum to 180 degrees and use this to solve problems.

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Year 5

Know that the angles on a straight line sum to 180 degrees and use this to solve problems

I know that the angles on a straight line sum to 180 degrees and use this to solve problems.

Download all resources

Share activities with pupils

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Lesson details

Key learning points

Angles on a straight line have a sum of 180 degrees.
To calculate missing angles you can use addition and subtraction.
Use mental or written strategies to calculate with angles up to 180 degrees.

Keywords

Sum - The sum is the result of adding two or more numbers.
Opposite - If something is opposite, it is placed on the other side.

Common misconception

Pupils think that the angles on a straight line only applied to lines that are horizontal.

Ensure pupils are exposed to straight lines in a range of orientations, encouraging them to draw on the 180 degree angle and how this can apply to both sides of the straight line.

You might like to create two straight lines that are joined by a split pin at the centre. Slowly rotate one of the lines around to reveal the angles it creates. Once pupils know the size of one of the angles, they can then identify the other angles by beginning to generalise about opposite angles.

Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).