Question

I need help please I don’t understand this

Answer 1

Answer:

cosB = 21/75, tanB = 72/21

Step-by-step explanation:

Here, we can use pythagoras to figure out all sides. 75^2-72^2 = 21^2. So, we have sides with lengths 21, 72, and 75. We are given that sinB = 72/75. The definition of sin is opposite of hypotenuse. So, the opposite of angle B is side CA and the hypotenuse is BA. This allows us to find that BC is the 21 length side. The cos of an angle is adjacent over hypotenuse. In this case, it is BC/BA which is 21/75. similarly, Tan is opposite over adjacent or 72/21. And we are done. Those are the values. TO remember these, use the acronym:

SOH CAH TOA. S refers to sin and OH refers to opposite over hypotenuse. Similarly C is cos, A is adjacent, and H is hypotenuse, and then T is tan,  o is opposite and A is adjacent.