Answer:
2.33
Step-by-step explanation:
imagine a circle. its center is A, and it goes through B, so its radius is AB.
then it is important to know that the sum of all the angles in a triangle is 180 degrees.
one angle (at C) is 90. the angle at B is 25. so, the angle at A is 180 - 90 - 25 = 65 degrees.
more back to our circle.
in this circle the line CB is the sine of the angle at A multiplied by the radius.
and AC is the cosine of the angle at A multiplied by the radius.
we can ignore the orientation + and - of these functions, as we are only interested in the absolute length (and we can mirror the triangle, and all the angles and side lengths still stay the same).
=> CB = sin(A)×AB
AC = cos(A)×AB
=> 5 = sin(65)×AB
=> AB = 5 / sin(65)
=> AC = cos(65)×5/sin(65) = 5 × (cos(65)/sin(65)) =
= 5 × cot(65) = 2.33