You can
put this solution on YOUR website!You may not already know that every triangle is made up of 180 degrees. Knowing this makes the question much easier!
In the question it tells you that the measurement of one angle is 30 degrees.
And you should already know that the other angle along the bottom side is 90 degrees, or a right angle (because otherwise the stairs would not be sturdy and would rock back and forth when you went up them).
180 = Angle 1 + Angle 2 + Angle 3
180 = 90 + 30 + x
180 = 120 + x
60 = x
So, the third angle must measure 60 degrees.
Check your answer again, to make sure you didn't make any mistakes.
60 + 30 + 90 = 180
Your answer is correct!