I can’t see the exact numbers because the pic is blurry but here’s how to solve it.
The three angles in a triangle always add up to 180. So subtract the angle that’s given and you’ll have the sum of the two other angles. Since it’s an equilateral triangle, the other two angles are the same.
So write the equation 2(whatever the angle is) = the number you get when you do 180-the given angle
For example (I’m not sure these numbers are right because the pic is blurry)
2(9x+7)=114
Then you would solve for x and once you get x, plug it into the angle expression 9x+ 7 or whatever to get the angle measure.
