Note: I am assuming we have to determine the angle 'Ф'.
Answer:
The value of Ф = 22.6°
Explanation:
Given
hypotenuse = 13
To determine:
Angle = Ф = ?
Using the trigonometric ratio
cos Ф = adjacent / hypotenuse
here
so substituting adjacent = 12, hypotenuse = 13 in the equation
cos Ф = adjacent / hypotenuse
cos Ф = 12 / 13
Ф = arccos (12/13)
Ф = 22.6°
Therefore, the value of Ф = 22.6°