Question

Find the side x, giving answer to 1 decimal place

Answer 1

10.8=x

Explanation:

Using the Law of Sines, we can put together the fact that

`(sin A)/(a) =(sinB)/(b)`

Substitute our given values from the triangle:

`(sin 81)/(x) =(sin40)/(7)`

Turn the sines into a decimal:

`(0.9876)/(x) =(0.6427)/(7)\\`

cross multiply using butterfly method

0.988·7=0.643x

solve for x

6.916=0.643x

divide both sides by 0.643

10.8=x (round to nearest tenth)

Hope this helps! :)

Answer 2

Set your calculator to degree mode.

Using the Law of Sines:

7/sin(40°) = x/sin(81°)

x = 7sin(81°)/sin(40°) = 10.8