Question

In ΔDEF, the measure of ∠F=90°, FD = 63 feet, and DE = 71 feet. Find the measure of ∠E to the nearest degree.

Answer 1

Answer:

Triangle DEF is a right

angled triangle with ∠F = 90 degrees

and ∠E = 83 degrees.

Using Cosine ratio:

Cos(83) = adjacent/hypotenuse

Cos(83) = 79/ hypotenuse

Hypotenuse (DE) = 79/cos(83)

DE = 648.2 feet

Hope this helps :-)