Answer:
cos theta = 5/13
Step-by-step explanation:
sin theta = opp side / hypotenuse
opp side = 12 and hypotenuse = 13
Using the pythgorean theorem
opp ^2 + adj ^2 = hypotenuse ^2
12 ^2 + adj^2 = 13^2
144 + adj ^2 = 169
adj^2 = 169-144
adj^2 = 25
Taking the square root of each side
adj = 5
cos theta = adj / hypotenuse
cos theta = 5/13
