Geometry and measuresKS3 / GCSE

Alternate angles in parallel lines

Use alternate angles to find missing angle.

  • Check that the lines are marked as parallel.
  • Alternate angles are equal.

Example 1

The marked lines are parallel. Find angle .

Alternate angles are equal.

Example 2

The marked lines are parallel. Find angle .

Alternate angles are equal.

Your turn

Question 1

The marked lines are parallel. Find angle .

Check answer
Alternate angles are equal.
Question 2

The marked lines are parallel. Find angle .

Check answer
Alternate angles are equal.
Question 3

The marked lines are parallel. Find angle .

Check answer
Alternate angles are equal.
Question 4

The marked lines are parallel. Find angle .

Check answer
Alternate angles are equal.
Question 5

The marked lines are parallel. Find angle .

Check answer
Alternate angles are equal.
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