A because linear means straight line
1st :The angle of depression 30° = the angle of elevation (from the truck to the height of the building.
2nd :
cos 30° = (adjacent side)/(hypotenuse)
cos 30° = x/100, but cos 30°= (√3)/2
(√3)/2 = x/100 and x = (100√3)/2
and x = (50.√3) = 86.60 m
A will be 7 x 5
B will be 10x10
What you have to do is multiply 21 by 2. it is 42. $42 dollars was the original price of the bookcase.
