The second angle of a triangle is twice the first angle. The third angle is 20 degrees more than the first angle. What is the first angle?
Let A1,A2,A3 be the angles of the triangle
We know, A1+A2+A3 = 180 -------(1)
given A2=2(A1) ------(2)
A3= A1+20 --------(3)
Putting 2 & 3 in 1 , we get
Let x be first interior angle of the triangle. Then, second and third interior angles will be
The sum of the measures of the interior angles of a triangle is 180 degrees: