Question

Triangle ABC has side lengths of a equals 15 three equals 15 square root three and C equals 30 inches part a determine the measure of angle be part B show how to use the unit circle to find Tandy part C calculate the area of triangle ABC

Answer 1

∠B = 60°

Step-by-step explanation:

Let us first draw the triangle.

Now the law of cosines gives

`(15√(3))^2=30^2+15^2-2(15*30)cosB`

which simplfies to give

`675=1125-900cosB`
`\Rightarrow2\cos B=1`
`\cos B=(1)/(2)`

Solving for B gives

`B=\cos^(-1)((1)/(2))`

Using a calculator we get

`\boxed{B=60^o}`

which is our answer!