Answer:
Measure of the acute angle = 84°
Explanation:
In the figure attached,
ABDE is a swimming pool having length 'AB' = 65 feet
Depth of one end of the pool is BE = 4 feet
And depth of the other end AD = 11 feet
Acute angle between the bottom of the pool (DE) and wall of the deep end (AD) is ∠ADE.
Now from ΔCDE,
tanx =

tanx =

x =

x = 6.15°
Now measure of acute angle the bottom of the pool makes with wall at he deep end,
m∠ADE = (90 - 6.15)°
= 83.85°
≈ 84°