## samalami 2 years ago PLEAAASSEEE help Pre Calc: thank you so much picture posted below xoxo vvv

1. samalami

2. jim_thompson5910

you first have to use the pythagorean theorem to find the length of AB

3. jim_thompson5910

AC^2 + BC^2 = AB^2 36^2 + 24^2 = x^2 1296 + 576 = x^2 keep going to solve for x

4. samalami

x=+/- 12 to the power of 13

5. samalami

@jim_thompson5910

6. jim_thompson5910

you mean $\Large x = \pm 12\sqrt{13}$ right?

7. samalami

yes :) @jim_thompson5910

8. jim_thompson5910

since AB is the length and x is the length, we only consider positive lengths so $\Large x = 12\sqrt{13}$ which means $\Large AB = 12\sqrt{13}$

9. jim_thompson5910

now use the definition of sine, plug in the lengths, and simplify sin(angle) = opposite/hypotenuse sin(A) = 24/(12*sqrt(13)) sin(A) = 2/(sqrt(13)) sin(A) = (2*sqrt(13))/(sqrt(13)*sqrt(13)) sin(A) = (2*sqrt(13))/(13)

10. samalami

ughhh thank you so much! FINALLY I understand this nonsense.

11. jim_thompson5910

that's great