Question

topic 2 assessment form a what is the value of y? a. 42 b. 85 c. 88 d. 95

Explanation:

Step1: Use linear - pair property

The angle adjacent to the $124^{\circ}$ angle on the straight - line has a measure of $180 - 124=56^{\circ}$ since linear pairs of angles are supplementary.

Step2: Find the third angle in the triangle

In the triangle where one angle is $56^{\circ}$ and another is $39^{\circ}$, using the angle - sum property of a triangle ($\text{sum of angles in a triangle}=180^{\circ}$), the third angle $z$ in this triangle is $180-(56 + 39)=85^{\circ}$.

Step3: Use vertical - angle property

Since $y$ and $z$ are vertical angles, and vertical angles are equal, $y = z$. So $y=85^{\circ}$.

Answer:

B. 85