Step-by-step explanation:
a. the angle B in triangle ABC:
180-47=133°
angle C in ABC:
180-(40+133)=7°
using sine rule:
a/sin A= b/sin B= c/sin C
50/sin 7= BC/sin 40
BC= (50*sin40)/ sin7
=263.7 m
b.sin 47= opposite/hypotenuse
sin 47= CD/263.7
CD= sin 47*263.7
= 192.9
