Angles in parallel lines
An introduction to alternate, corresponding and co-interior angles in parallel lines
Parallel lines are lines which are always the same distance apart and never meet. Arrowheads show lines are parallel.
When a pair of parallel lines is cut with another line known as an intersecting transversal, it creates pairs of angles with special properties.
Corresponding angles
Corresponding angles are equal. The lines make an F shape. Notice that the F shape can be upside down or back to front.
Alternate angles
Alternate angles are equal. The lines make a Z shape which can also be back to front.
Vertically opposite angles
Vertically opposite angles are equal.
Question
Calculate the angles \(x\) and \(y\). Give reasons for your answers.
\(x\) is \(50^\circ\). Corresponding angles are equal.
\(y \) is \(180 - 50 = 130^\circ\). Angles on a straight line add up to 180掳.