Question

What's the answer to this math picture please?

Answer 1

m<BGC = 145°

Explanation:

<AGC and <DGB are vertical angles. Vertical angles are congruent. Therefore:

m<AGC = m<DGB

`3x + 20 = 8x - 5` (substitution)

Collect like terms

`3x - 8x = -20 - 5`

`-5x = -25`

Divide both sides by -5

x = 5

m<BGC = 180 - (m<AGC) (linear pair)

m<BGC = 180 - (3x + 20)

Plug in the value of x

m<BGC = 180 - (3(5) + 20) = 180 - 35

m<BGC = 145°