Question

In ΔDEF, the measure of ∠F=90°, the measure of ∠D=19°, and DE = 40 feet. Find the length of EF to the nearest tenth of a foot.

Answer 1

13

Explanation:

Answer 2

13.0feet

Explanation:

Given ΔDEF with ∠F=90°, the measure of ∠D=19°, and DE = 40 feet, since one of the angles of the triangle is 90°, the triangle is a right angled triangle as shown in the attachment.

Using SOH, CAH, TOA to get the unknown EF.

Since <D is opposite to side EF, EF will be the opposite while side DE will be the hypotenuse

Based on SOH:

Sin<D = Opposite/Hypotenuse

Sin<D = EF/DE

Sin19° = EF/40

EF = 40sin19°

EF = 13.0 feet to the nearest tenth of a foot