
Gabriel F. answered 01/21/21
Experienced High School Tutor Specializing in Math and Science
Remembering our trigonometric functions relationships (SOH-CAH-TOA):
Sin(A) = Opposite side/ Hypotenuse
Cos(A) = Adjacent side/ Hypotenuse
Tan(A) = Opposite side/ Adjacent side
In this figure, with respects to angle A:
Opposite side= 12
Adjacent side= 5
Hypotenuse= 13
Plugging these values in to any of the trigonometric functions:
Sin (A) = 12/13
Therefore:
Sin -1(12/13)= A
A=67.38 degrees
If you use any of the other functions, the answer will be the same:
Cos (A) = 5/13
Therefore:
Cos-1(5/13) = A
A = 67.38 degrees
Tan(A) = 12/5
Therefore:
Tan-1(12/5)=A
A = 67.38 degrees
***NOTE: Make sure your calculator is in degrees.