geometry
posted by roxie .
The coordinates of the vertices of CDE are C(1, 4), D(3, 6), and E(7, 4). If the triangle is reflected over the line y = 3, what are the coordinates of the image of D?

all your x's will stay the same
for D(3.6), D is 3 units above y = 3
so the reflection in y = 3 would put it 3 units below,
resulting in D1(3,0)