Let sin? = 4/5, and cos? = ?3/5, and find the indicated value

Let the unknown angle be x.

That is

sin x = 4/5

cos x = 3/5

By drawing a right triangle in the first quadrant,

hypotenuse = 5

Adjacent side = 3

opposite side = 4

That is tan x = 4/3

From the calculator,

x = arctan (4/3) = 53 deg (nearest integer)

Answer: 53 deg. (nearest integer)