27) a man on the third floor of a building shouts down to a person on the street. if the man is 25 feet up and the distance between the person on the street and the man in the building is 50 feet, what is the angle of elevation (in degrees) between the person on the street and the person in the building?
a) 15°
b) 30°
c) 45°
d) 60°

Option B) 30°

Step-by-step explanation:

Given :  A man on the third floor of a building shouts down to a person on the street. If the man is 25 feet up and the distance between the person on the street and the man in the building is 50 feet.

To find : What is the angle of elevation (in degrees) between the person on the street and the person in the building?

Solution :

According to question, a rough diagram is framed which shows the position of  man on street and man on building.

Refer the attached figure below.

A man on the third floor of a building is 25 feet up i.e. AB=25 feet.

The distance between the person on the street and the man in the building is 50 feet i.e. BC=50 feet.

We have to find the angle of elevation i.e. ∠C.

It form a right angle triangle,

Applying sin property of trigonometric,

Therefore, Option B is correct.

The angle of elevation is 30°.

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4