Did you mean, how far is B from A?
You just said it is 200 km from C.
Make a sketch
I have triangle ABC, with BC = 200, CA = 300 and angle C = 147°
Use the cosine law to find BA
City A is 300km due east of city B.city C is 200km on an bearing of 123degree from city B how far is it from C.
2 answers
All angles are measured CW from +Y-axis.
BA = 300km[90o].
BC = 200km[123o].
CA = 300km[90o] - 200km[123o].
X = 300*sin90 - 200*sin123 = 132.3 km.
Y = 300*Cos90 - 200*Cos123 = 109 km.
CA = sqrt(X^2 + Y^2).
y
c
BA = 300km[90o].
BC = 200km[123o].
CA = 300km[90o] - 200km[123o].
X = 300*sin90 - 200*sin123 = 132.3 km.
Y = 300*Cos90 - 200*Cos123 = 109 km.
CA = sqrt(X^2 + Y^2).
y
c
2 answers