Question

Given the following triangle,

If Sin F = 3/5

, then find the Cos D:
Responses

4/3

3/4

3/5

4/5

Answer 1

Cos D = 3/5

Explanation:

We know that the sine ratio is sin (angle) = opposite/hypotenuse. Thus, sin F = 3/5 indicates that

• the side opposite angle F is 3 units (side MD),
• and the hypotenuse is 5 units (side DF)

The cosine ratio is cos (angle) = adjacent/hypotenuse.

When D is the reference angle, side MD is the adjacent side and DF is the hypotenuse.

Because MD = 3 units and DF = 5 units, Cos D = 3/5