Question

If anyone know the answer I need it. Thank you the question is what is the length of AB

Answer 1

7
`√(2)`

Explanation:

In this question, we are going to either use the formula with tan, sin or cos.

We have the angle, which is θ, BC which is the opposite side, and we must find the length of AB which is the hypotenuse. So we are going to use the formula:

sin θ =
`(opposite)/(hypotenuse)`

sin 45 =
`(7)/(hypotenuse)`

hypotenuse =
`(7)/(sin45)`

hypotenuse = 9.899494937... which is also equal to 7
`√(2)`

If you check with the other options:

`√(2)` = 1.414213562... which is wrong

1 which is obviously not the answer

7 which is also obvious.

∴ 7
`√(2)`, which is the 3rd option, is the answer.

Answer 2

The answer to this question is choice C.

Explanation:

In order to solve this question, I first recognized which trigonometry function that I could use. I realized that I am given information about angle a which is 45 degrees and that the length of the side opposite to it is 7 units. Therefore, I used the sine function to create a mathematical equation which was sine(45) = 7/AB. I isolated AB, to get the equation AB = 7/sine(45) which I plugged into a calculator to get 9.899 which is closest to choice C.