Answer:Answer:
13.0feet
Step-by-step 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