Angles on a straight line
The question
degrees
Angles on a line: x, 45°, 90°
How it works.
45° + 90° + x=180°
45° + 90°=135°
180° − 135°=45°
- 01
The angles on a straight line add up to 180°, so all three together make 180°.
- 02
Add the two you are given first: 45 + 90 = 135.
- 03
Then take that from 180°: 180 − 135 = 45. So x = 45°.