Answer:
∠ABC= 180° -21° -37° (∠ sum of triangle ABC)
∠ABC= 122°
Using sine rule,
[tex] \frac{AB}{sin21°} = \frac{200}{sin122°} [/tex]
AB= 200(sin21°)/sin 122°
AB= 84.5 units (3 s.f.)
[tex] \frac{BC}{sin37°} = \frac{200}{sin122°} [/tex]
BC= 200(sin37°)/ sin122°
BC= 142 units (3 s.f.)
