Answer:
BC 136m, AB 89m
Explanation:
Find the diagram attached
According to sin rule;
a/sinA = b/sinB = c/sinC
From the diagram;
b = 120m
<B = 60degrees
<C = 40degrees
From the sine formula
b/sinB = c/sinC
120/sin60 = c/sin40
csin60 = 120sin40
c = 120sin40/sin60
c = 120(0.6428)/0.8660
c = 77.1345/0.8660
c = 89.06
c = AB = 89m
Get BC;
According to the sine rule
a/sinA = b/sinB
a/sin(180-100) = 120/sin60
a/sin80 = 120/sin60
asin60 = 120sin80
a = 120sin80/sin60
a = 120(0.9848)/0.8660
a = 118.177/0.8550
a = 136.46
Hence a = BC = 136m