Question

In ️LMN, m=2.1 inches, n=8.2 inches and

Answer 1

Step 1

Draw the triangle

Step 2

State the given parameters

l = ?

n= 8.2 in

m = 2.1 in

Step 3

solve for l to the nearest tenth of an inch

Using the cosine rule we can find the value of l

The cosine rule is given as

`l^2=n^2+m^2-2nm\cos L`

Substituting the given values into that equation, we have

`l^2=8.2^2+2.1^2-(8.2*2.1*\cos \text{ 85)}`
`l\text{ =}\sqrt[]{67.24+4.41-(1.50082189)}`
`\begin{gathered} l\text{ =}\sqrt[]{70.14917811} \\ l\text{ =8.375510618 inches} \end{gathered}`

To the nearest tenth of an inch l = 8.4 inches