Answer:
Explanation:
3x + x + 60 = 180.
first, we add the x's together.
4x + 60 = 180
then we see if they all have a common multiple. in this case, they do. they are all divisible by 4, so we can use that.
x + 15 = 45
then, just subtract 15 from both sides, that way we get the variable by itself.
x = 30
also, it is a right triangle. the top angle (3x) multiplied by 3 is 90. any triangle that has a 90 degree angle is automatically a right triangle.