Respuesta :

The angles at the base are congruent, because the triangle is isosceles. The remaining angle is supplementary with 3x, so it is [tex] 180-3x [/tex]

So, the sum of the three angles is

[tex] (x+15)+(x+15)+(180-3x) = 210-x [/tex]

And the sum of the angles of a triangle is always 180:

[tex] 210-x = 180 \iff x = 210-180 = 30 [/tex]

The 3 angles in the triangle add up to 180 degrees.

So x + 74 + 73 + 37 + x = 180

2x = 180 - 74 - 73 - 37 = -4

x = -2   answer


3x = 2(x + 15)

x = 30  answer