math trig
posted by mier .
A TOWER AND A MONUMENT STAND ON A LEVEL PLANE.THE ANGLES OF DEPRESSION OF THE TOP AND BOTTOM OF THE MONUMENT VIEWED FROM THE TOP OF THE TOWER ARE 13DEGREE AND 31 DEGREE,RESPECTIVELY;THE HEIGHT OF THE TOWER IS 145 FT. FIND THE HEIGHT OF THE MONUMENT.

draw the figure. let h height of momnument. Let d be the distance from the bottom of the tower to the bottom of the monument.
Draw a dotted horizonal plane from the top of the monument to the tower. Let the distance from this line to the top of the tower be 145h
from the lower triangle, d/145=sin(9031) solve for d.
Now knowing d, look a the top triangle (base dotted line
d/(145h)=sin((9013) you know d, so solve for h. 
143