Question

Which equation can be used to find the measure of angle LKJ?

cos−1(StartFraction 8.9 Over 10.9 EndFraction) = x
cos−1(StartFraction 10.9 Over 8.9 EndFraction) = x
sin−1(StartFraction 10.9 Over 8.9 EndFraction) = x
sin−1(StartFraction 8.9 Over 10.9 EndFraction) = x

Answer 1

D.
`sin^(-1) ((8.9)/(10.9) ) = x`

Explanation:

Sin is used to find the side length of a right triangle using angle degrees. However, this is using the inverse. The ratios are still the same, though.

sin(x) = 8.9/10.9 because it is the opposite side's length over the hypotenuse length. Making it the inverse would make it D.

Answer 2

fourth option

Explanation:

Using the sine ratio in the right triangle.

sin JKL =
`(opposite)/(hypotenuse)` =
`(JL)/(KJ)` =
`(8.9)/(10.9)` , thus

x =
`sin^(-1)` (
`(8.9)/(10.9)` )