Question

Given ABCD with A = (1,1), B = (4, 2), C = (4, 5), and D = (1, 4), what are the coordinates for Point D' if the y-axis is the reflecting line?

Answer 1

Conditions

Given ABCD with $A = (1,1)$ , $B = (4,2)$ , $C = (4,5)$ , and $D = (1,4)$ , what are the coordinates for Point D' if the y-axis is the reflecting line?

Solution

Consider the graph:

This is our quadrangle ABCD.

If $y$ -axis is the reflecting line, then for all points of this quadrangle, $y$ -coordinate will not change, $x$ -coordinate changes its sigh. That's why reflected figure will have the following coordinates:

(1-,1), (-4,2), (4-,5), (-1,4), as shown on a graph below:

So, the coordinates of D' are (-1,4)