What are alternate angles on parallel lines?

Alternate angles are angles that occur on opposite sides of the transversal line and have the same size. Each pair of alternate angles around the transversal are equal to each other. The two angles can either be alternate interior angles or alternate exterior angles.

How do you find alternate angles in parallel lines?

Video quote: And they link to the line which crosses them a common way that's taught to spot alternate angles is to look for a Z shape.

What are the angles in parallel lines?

Angles that are in the area between the parallel lines like angle H and C above are called interior angles whereas the angles that are on the outside of the two parallel lines like D and G are called exterior angles. Angles that are on the opposite sides of the transversal are called alternate angles e.g. H and B.

What does alternate mean in parallel lines?

When two straight lines are cut by a transversal, then the angles formed on the opposite side of the transversal with respect to both the lines are called alternate angles. The pairs of alternate angles in the above figure are: … ∠3 and ∠5. ∠4 and ∠6.

Do alternate angles add up to 180?

Unless the alternate interior vertical angles are 90° then they will not add up to 180°. If the alternate interior angles are obtuse, then adding them together will result in a number higher than 180°. Therefore, if the alternate interior angles are acute, then adding them together will result in a number below 180°.

What is alternate angle example?

Alternate angles are shaped by the two parallel lines crossed by a transversal. Consider the given figure, EF and GH are the two parallel lines. If two parallel lines are cut by a transversal, then the alternate angles are equal.

Are alternate interior angles parallel?

Alternate interior angles are formed by a transversal intersecting two parallel lines . They are located between the two parallel lines but on opposite sides of the transversal, creating two pairs (four total angles) of alternate interior angles. Alternate interior angles are congruent, meaning they have equal measure.

What does alternate mean in maths?

The word ‘alternate’ is usually used with pairs of angles, to indicate that each is on opposite sides of a line. In the figure below, the two angles are called alternate angles because they are on opposite sides of the sloping transversal line.

What is the alternate angle theorem?

Alternate Interior Angle Theorem



The Alternate Interior Angles Theorem states that, when two parallel lines are cut by a transversal , the resulting alternate interior angles are congruent .