Corresponding angles, step by step
Where one line crosses two parallel lines, angles in matching positions are equal.
The question
40° and x
40°andx
correspondingangles
40°=x
x=40°
- Start with the arrows: they say the two lines are parallel. Without that, none of the angle facts apply and this picture would not have an answer.
- Now find where the two marked angles sit. They are in the same corner at each crossing — both above their line and both on the same side of the slanted one. That makes them corresponding angles.
- Corresponding angles are equal, so x is the same as the angle already marked. x = 40°. Nothing to work out — but only once you have seen which pair it is.
How it works.
- 01
Start with the arrows: they say the two lines are parallel. Without that, none of the angle facts apply and this picture would not have an answer.
- 02
Now find where the two marked angles sit. They are in the same corner at each crossing — both above their line and both on the same side of the slanted one. That makes them corresponding angles.
- 03
Corresponding angles are equal, so x is the same as the angle already marked. x = 40°. Nothing to work out — but only once you have seen which pair it is.