Question

if $angle7 = 4b + 25$ and $angle2 = 145^{circ}$ are alternate exterior angles, what is the value of $b$?
a. 25
b. 20
c. 30
d. 15

Explanation:

Step1: Recall angle - property

Alternate exterior angles are equal. So, $\angle7=\angle2$.

Step2: Set up the equation

$4b + 25=145$.

Step3: Solve for $b$

Subtract 25 from both sides: $4b=145 - 25$. So, $4b = 120$.

Step4: Find the value of $b$

Divide both sides by 4: $b=\frac{120}{4}=30$.

Answer:

B. 20