Question

20) Find angle Dd= 54.9 cm, f= 69.2 cm, F = 56°

Answer 1

Using sine rule formula to resolve the value for angle D

The sine rule formula is,

$\frac{sinD}{d}=\frac{sinF}{f}$

Given:

$\begin{gathered} d=54.9cm \\ f=69.2cm \\ F=56^0 \end{gathered}$

Therefore,

$\frac{sinD}{54.9}=\frac{sin56^0}{69.2}$

Simplify

$\begin{gathered} sinD=\frac{54.9\times sin56^0}{69.2}=0.65771911464 \\ D=sin^{-1}(0.65771911464)=41.12615063003\approx41^0(nearest\text{ degree\rparen} \\ D=41^0 \end{gathered}$

Hence, the answer is

$\angle D=41^0$