Question

CAN SOMEONE HELP PLEASE
m4A=42°, b=10, c= 12. What is the length of a to the nearest tenth?

Answer 1

a = 8.1

Explanation:

Use the cosine rule:

`a = √(b^2 + c^2 -2 bc \space\ cosA )`

Substituting the values:

`a = √(10^2 + 12^2 -2(10)(12) \space\ cos 42 \textdegree\ )`

⇒
`a = √(4 \space\ cos 42\textdegree\ )`

⇒
`a = 8.1`