Question

problem 10: (first taught in lesson 18) given that $overline{ed}paralleloverline{ab}$, select which type of angle pair $angle ecd$ and $angle acb$ are and then tell whether the angles are congruent or supplementary.
a
b
c
d
e
vertical angles; congruent

Explanation:

Step1: Identify angle - pair type

$\angle ECD$ and $\angle ACB$ are vertical angles as they are opposite angles formed by the intersection of two lines.

Step2: Determine congruence

Vertical angles are always congruent. So, $\angle ECD\cong\angle ACB$.

Answer:

A. Vertical angles; congruent