Each 2 triangles should be congruent to each other
The measure of angle 4 would be the same as its opposite exterior angle which is given. It will have a measurement of 38 degrees. These angles are called alternate exterior angles. Hope this answers the question. Have a nice day. Feel free to ask more questions.
Answer + Step-by-step explanation:
1) D be the symmetric of B with respect to C then CD = BC
A the symmetric of C with respect to B then AB = BC
We obtain :
CD = BC
AB = BC
Then AB = CD
2) m∠SBA = 180 - SBC = 180 - SCB = m∠SCD
3) we have :
BA = CD
BS = CS
m∠SBA = m∠SCD
Then
the triangles SBA and SCD are congruent
4)
the triangles SBA and SCD are congruent Then SA = SD
Therefore SAD is an isosceles triangle.
I think 17.2 sorry if im wrong