Corresponding angles — Grade 8 Math, what it means and where it is taught
Same position at each crossing. Equal when the lines are parallel.
Taught in Grade 8 Math.
Where it is taught
Practise this idea
5 questions in the course bank use Corresponding angles, in Dilations & Similarity, Angle Relationships, How to Write a Proof.
Problem 1
Which is always true for two similar figures?
- Corresponding angles are equal
- Corresponding sides are equal
- Perimeters are equal
- Areas are equal
Worked answer
Corresponding angles are equal
Angles never change under a dilation
Sides change by the factor k
So only the angle statement is always true
Problem 2
Two parallel lines are cut by a transversal. One angle is 64°. Find its corresponding angle.
Worked answer
64
Same position at the other crossing
64°
Problem 3
Two parallel lines are cut by a transversal. Corresponding angles measure (2x + 15)° and (4x - 25)°. Find x.
Worked answer
20
2x + 15 = 4x - 25
40 = 2x
x = 20
Problem 4
Which pair of angles is not necessarily equal when two parallel lines are cut by a transversal?
- Co-interior angles
- Corresponding angles
- Alternate interior angles
- Vertical angles
Worked answer
Co-interior angles
Co-interior angles are supplementary, not equal
They are only equal in the special case of 90° each
Problem 5
You are given that AB ∥ CD. What angle relationship does a transversal give you?
Worked answer
congruent alternate interior angles
Alternate interior angles are congruent.
Corresponding angles are congruent too.