Answer:
(1)
Step-by-step explanation:
the sum of the 3 angles in a triangle = 180° .
consider the inner triangle where
a + b + 58° = 180° ( subtract 58° from both sides )
a + b = 122°
consider the outer triangle where
c + d + 63° = 180° ( subtract 63° from both sides )
c + d = 117°
Then
a + b + c + d = 122° + 117° = 239°
