Answer:
m<A = 69°
m<C = 69°
Explanation:
From the question given above, the following data were obtained:
AB = AC
m<B = 42°
m<A =?
m<C =?
Since:
AB = AC
Therefore,
m<A = m<C
A + B + C = 180 (sum of angles in a triangle)
C + 42 + C = 180
Collect like terms
C + C = 180 – 42
2C = 138
Divide both side by 2
C = 138 / 2
C = 69°
Finally, we shall determine m<A. This can be obtained as follow:
m<A = m<C
m<C = 69°
Therefore,
m<A = 69°