Answer:
=
= 0.83
Explanation:
The key understanding here is that ΔJKL is similar to triangle 3 based on the AA criterion (they both have a right angle and a 40° angle).
We can find
by setting up a proportion statement that includes KL, JL, and the lengths of their corresponding sides in triangle 3.
We can use this proportion:
=
⇒ opposite to 40° angle
KL, JL ⇒ ΔJKL
⇒ adjacent to 40° angle
6.4, 7.7 ⇒ triangle 3
[Now see the attachment]
Now we can rewrite the equation to show the ratios of the side lengths within each triangle.
=
⇒ ΔJKL
KL, 6.4 ⇒ adjacent to 40° angle
⇒ triangle 3
JL, 7.7 ⇒ adjacent to 40° angle