Answer:
D. cosine
Step-by-step explanation:
As it can be seen in the figure, the triangle ABC is a right-angled triangle with Angle C = 90 degree.
In a right angle triangle, there is a formula as following:
cosine (of an acute angle) = length of adjacent side/ length of hypotenuse
In the figure, the point of angle B and length of hypotenuse AB are given.
We have to calculate x - length of the given side. As BC is the adjacent side of angle B
=> we can use the above formula to calculate x
So that we can use cosine
