Question

In ΔDEF, the measure of ∠F=90°, ED = 65, FE = 56, and DF = 33. What is the value of the cosine of ∠D to the nearest hundredth?

Answer 1

Answer:

$cos(D)=0.51$

$m\angle D=59.49^o$

Step-by-step explanation:

we know that

In the right triangle DEF

$cos(D)=\frac{DF}{ED}$ ---> by CAH (adjacent side divided by the hypotenuse)

substitute the given values

$cos(D)=\frac{33}{65}=0.51$

using a calculator

$m\angle D=cos^{-1}(\frac{33}{65})=59.49^o$