Answer:
it's -63
good luck if you want explanation comment
Answer: 63
Step-by-step explanation:
All triangles' angles added up should be 180 degrees, so 70+47=117 and 180-117=63.
180 = a+b+c
180 = 47 + 70 + c
180 - 47 - 70 = c
or,
180 - (47+70) = c
