Question

What is the cosine of angle F

A. 4/5
B. 3/4
C. 5/4
D. 3/5​

Answer 1

D

Explanation:

Cosine is adjacent over hypotenuse.

adjacent to angle F is 15

over the hypotenuse being 25

reduced is 3/5

Answer 2

Answer: option D

Explanation:

Remember the cosine identity:

`cos\alpha=(adjacent)/(hypotenuse)`

Given the right triangle DFE shown in the image, you can identify that the adjacent side and the hypotenuse for the angle F of this triangle are:

`adjacent=15\\hypotenuse=25`

Now you can substitute values into
`cos\alpha=(adjacent)/(hypotenuse)` and then reduce the fraction.

THerefore you get:
`cos(F)=(15)/(25)\\\\cos(F)=(3)/(5)`