Respuesta :

Answer:

so first we will find the interior angle:  

1 angle :  31 (given )

2 angle :31 ( the base angles of isoscles triangle are equal)

3 angle : 31 + 31 + x = 180                     ( angle sum property of triangle)

              x = 180 - 62 = 118

now the exterior angles :

1 angle : 180 - 31 = 149 ( exterior angle and the angle adjacent usually forms  a line (= 180) )

2 angle : 149 ( same reason as the first)

3 angle : 180 - 118 = 62 (  same reason as the first)

( i dont know if there is any other way, but this is one)