Answer:
JK = 24
Step-by-step explanation:
Δ BKJ and Δ BCA are similar triangles and ratios of corresponding sides are equal, that is
=
, substitute values
=
( cross- multiply )
5JK = 120 ( divide both sides by 5 )
JK = 24
7 & 8/10 or 78/10 ( which is the same thing)
There isnt a image of the shape

Using the fact that cos is 2π-periodic, we have

That is,
for any
and integer
.

We get 2 solutions in the interval [0, 2π] for
and
,
