An equilateral triangle has two vertices at (0,5) and (8,5). If the third vertex is in the first quadrant, what is the y-coordinate? Express your answer in simplest radical form.
To be in Q I it will need to be ABOVE the line drawn..... the x - point it will be midway between the two points
x = 4
coordinate will be 4, y and the distance from either of the given points will be 8
use distance formula from 0,5 (easiest) and 4,y to find the distance 8
8^2 = (4-0)^2 + (y-5)^2 solve for y