This trig question has me confused please help

Question

use the fundamental identities to find the value of the trigonometric function. Find tan theta, given that sin theta = 3/4 and theta is in quadrant II

Answer 1

sin(theta) = 3/4 = opposite side over hypotenuse.

adjacent side squared = 4^2 - 3^2 = 16-9 = 7

adjacent side = -sqr7

tan(theta) = opposite side over adjacent side = 3/-sqr7 = -3/sqr7