Distance of the person from the building (x)
tan 24 = 20/x => x = 20/tan 24 = 44.92 ft
The height of the building above the height of the person and the distance of the person from the building forms two legs of right angled triangle.
Therefore, if h is the height of the building, then;
tan 31 = (h-20)/44.92
h-20 = 44.92 tan 31
h = (44.92 tan 31) + 20 = 26.99 + 20 = 46.99 ft
5.46/0.25= 21.84 hope it helps
A=1/2 b*h
So substitute it in 1/2*1/2*4
1/2*1/2= 1/4
1/4*4= 4/4= 1 so the entrance is 1 foot tall
I answered the last post, the third option is correct
