Answer:
45
Step-by-step explanation:
First we want to understand the Base Angles Theorem
The Base Angles Theorem tells us that the base angles or the two bottom angles of an isosceles triangle are congruent.
Using this theorem, we can say that angle A and angle G are congruent meaning m∠A = m∠G. We can then write both of them as x.
We can create the equation ∠N + ∠A + ∠G = 180 degrees.
Knowing ∠N and knowing ∠A + ∠G = 2x, we can rewrite the equation into
90 + 2x = 180
We can then solve for x,
90 + 2x - 90 = 180 - 90
2x = 90
2x / 2 = 90 / 2
x = 45 degrees