Question

triangle ABC is right-angled at B. If angle A= 30 degree and AB= 9 cm, find BC and AC.

Answer 1

cos 30=AB/AC
ie,√3/2=9/AC
    AC=18/√3=6√3
tan30=BC/AB
 1/√3=BC/9
 BC=3√3

Answer 2

AB=9CM

BY TAN 30 = $1 \sqrt{3}$

WE GET BC= $3 \sqrt{3}$

AND BY PHYTHAGORAS THEOREM WE GET AC=  6$\sqrt{3}$