# 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?

##### 2 Answers

Dec 8, 2015

A1=40

#### Explanation:

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

A1+2(A1)+A1+20=180

A1=40

Dec 8, 2015

#### Explanation:

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: