Question

Please I need help!!!!!

Answer 1

for c:

`\begin{gathered} c^2=a^2+b^2-2ab\cos C \\ c^2=4^2+5^2-2(4)(5)\cos 100 \\ c^2=16+25-40\cos 100 \\ c^2=41-40\cos 100 \\ c^2=47.945 \\ c=\sqrt[]{47.945} \\ c=6.92 \end{gathered}`

for A:

`\begin{gathered} (c)/(\sin C)=(a)/(\sin A) \\ \sin A=(a*\sin C)/(c) \\ \sin A=(4*\sin 100)/(6.92) \\ A=\sin ^(-1)(4*\sin 100)/(6.92) \\ A=34.7 \end{gathered}`

for B:

`180-100-34.7=45.3`

answer: D