SOLUTION: If the sum of two angles of a triangle is equal to the third angle, prove that the triangle is right-angled?

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Question 353947: If the sum of two angles of a triangle is equal to the third angle, prove that the triangle is right-angled?
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
(x+y)=z
(x+y)+z=180
Since z=x+y then:
z+z=180
2z=180
z=180/2
z=90 degrees.