Can someone me ? i’m really struggling in this subject. you

Your answer would be 32.68° to two decimal places.

When finding an angle in a triangle that does not have a right angle, and we are given all 3 sides, we can use the cosine rule.

The cosine rule to find a side is , but since we are finding an angle, we need to use the formula .

With each side being the same letter as its opposite angle, so side CB would be labeled as it lies opposite angle A, we can input the values of the sides. This gives us:

, which we can type into a calculator to give us the fraction .

Because this fraction is equivalent to COS(B), we need to find the inverse of cosine so that we can get "B =", which means we do and in the calculator that gives us 32.6834, or 32.68 to 2 decimal places.

I hope this helps! Let me know if you have any questions :)

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.