An arrow is shot from a bow at 20.0 m/s at an angle of 65º above the horizontal. the arrow leaves the bow at a height of 1.80 m. at what height will it strike a wall that is 10.0 m away? (remember to connect the two motions of the arrow using time.)

In vertical motion the arrow will be accelerating so we can use equation of motion 
but first we need to find initial vertical and horizontal velocity

Horizontal velocity
cos65=x( horizontal)/20
x=8.45m/s 
Thus now we can calculate time after which it strike the wall
8.45=10/t
t=1.18 s this speed in horizontal will remain constant
vertical intial velocity
sin65=y(vertical)/20
y=18.13 m/s
use the equation of motion to calculate height
s=ut+1/2 at^2
s=(18.13)(1.18)+ 1/2 (-9.8)(1.18^2)
s=21.40-6.822
s=14.58 m
but as it is already 1.80 above ground  
So
The height of wall be =14.58+1.80=16.38m
ANSWER 16.38 meters