Question

1. in a sports field design, if ∠3 = 3y + 25 and ∠6 = 5y - 15 are alternate interior angles, what is the measure of ∠6 when y = 20?

a. 100 degrees
b. 95 degrees
c. 90 degrees
d. 85 degrees

Explanation:

Step1: Substitute y value

Given $\angle6 = 5y - 15$ and $y = 20$. Substitute $y = 20$ into the expression for $\angle6$. So we get $\angle6=5\times20 - 15$.

Step2: Perform multiplication

First, calculate $5\times20=100$. Then the expression becomes $\angle6 = 100 - 15$.

Step3: Perform subtraction

$100-15 = 85$. So the measure of $\angle6$ is 85 degrees.

Answer:

D. 85 degrees