Question

In ΔCDE, the measure of ∠E=90°, the measure of ∠D=38°, and DE = 12 feet. Find the length of CD to the nearest tenth of a foot.

Answer 1

51.6

Explanation:

its because you have to use cos toh and all of the calculator functions

Answer 2

Given:

Given that the triangle CDE is a right triangle.

The measure of ∠E is 90° and ∠D is 38°

The length of DE is 12 feet.

We need to determine the length of CD.

Length of CD:

The length of CD can be determined using the trigonometric ratio.

Thus, we have;

`cos \ \theta=(adj)/(hyp)`

where
`\theta=D` and the side adjacent to angle D is ED and hypotenuse is CD.

Substituting these values, we get;

`cos \ D=(ED)/(CD)`

where ∠D = 38°, ED = 12 feet.

Substituting, we get;

`cos \ 38^(\circ)=(12)/(CD)`

Simplifying, we have;

`CD=(12)/(cos \ 38^(\circ))`

`CD=(12)/(0.788)`

Dividing, we get;

`CD=15.2`

Thus, the length of CD is 15.2 feet.