Answer:
see explanation
Explanation:
You can find the sum of all interior angles of any convex shape with one simple equation: 180(n-2) , where n= number of sides of shape.
With a triangle, 180(3-2) simplified to, 180(1), with the answer being 180.
All the angles of a triangle add up to 180°
Lets look at first problem.
2x + 2x + x
set it equal to 180
2x + 2x + x = 180 (Combine like terms)
5x = 180 (Divide by 5, both sides)
x = 36
Next one,
7x + 3x + 90 = 180
10x + 90 = 180
10x = 90
x = 9
Last one,
2x + x + x = 180
4x = 180
x = 45