In ΔABC , angle C is a right angle. Which statement must be true?

A. sin A = cos B
B. sin A = tan B
C. sin B = tan A
D. sin B = cos B

 Choice A. sin(A) = cos(B)

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Explanation:

The rule is that sin(A) = cos(B) if and only if A+B = 90.

Note how

Since both result in the same fraction BC/AB, this helps us see why sin(A) = cos(B). Similarly, we can find that cos(A) = sin(B).

In the diagram below, the angles A and B are complementary, meaning they add to 90 degrees. So this trick only applies to right triangles.

The side lengths can be anything you want, as long as you're dealing with a right triangle.

the dimensions are:

step-by-step explanation:

we want to find the dimensions of a rectangular box with volume of

we factor to obtain;

we rewrite the rightmost factor to obtain;

recall that:

we apply difference of two squares formula to obtain;

hence the dimensions are

add all the numbers and check the ones place.

the answer is 486. as the ones place is more than 4, the estimation will be the next 10 ie, 490