+23254 Picture a right triangle with the right angle being ∠C. Label the other two angles ∠A and ∠B.
cos is defined to be the ratio of the adjacent side to the hypotenuse.
In this triangle, AB is the hypotenuse, side AC is the side adjacent to ∠A and side BC is the side opposite to ∠A.
cos∠A = 3/5 = AC/AB
Since this is a right triangle, use the Pythagorean Theorem to find the value of the third side:
AC² + BC² = AB² ---> 3² + BC² = 5² ---> BC = 4
sin is defined to be the ratio of the opposite side to the hypotenuse.
sin∠A = BC/AB = 4/5
tan is defined to be the ratio of the opposite side to the adjacent side.
tan∠A = BC/AC = 4/3
+23254 Picture a right triangle with the right angle being ∠C. Label the other two angles ∠A and ∠B.
cos is defined to be the ratio of the adjacent side to the hypotenuse.
In this triangle, AB is the hypotenuse, side AC is the side adjacent to ∠A and side BC is the side opposite to ∠A.
cos∠A = 3/5 = AC/AB
Since this is a right triangle, use the Pythagorean Theorem to find the value of the third side:
AC² + BC² = AB² ---> 3² + BC² = 5² ---> BC = 4
sin is defined to be the ratio of the opposite side to the hypotenuse.
sin∠A = BC/AB = 4/5
tan is defined to be the ratio of the opposite side to the adjacent side.
tan∠A = BC/AC = 4/3
