Answer:
3/4
Step-by-step explanation:
a1 = (-1/3)^0 = 1
r = -1/3
Hence S = 1/(1+1/3) = 1/(4/3) = 3/4
it is D
B=34, A=56
56 + 90 + B = 180
=) B=34
A is head to head with 56°.
