Question

Which equation can be used to find the missing angle?

a. X + 90 = 180
b. X + 40 = 90
c. 180 - 40 = x

Answer 1

b. x + 40 = 90

Explanation:

This is a right triangle, so we already know one of the angles is 90 degrees. The other angles combine to make the other 90 degrees. So, we have to figure out what the other angle is, as the second one is 40 degrees. To figure that out, use the equation x + 40 = 90. (This is extra, but x is 50, right?)

Answer 2

A, all three angles of a triangle equal 180