Recall that if a point (a,b) is reflected in the line y=x, then its image is (b, a).
Practice makes perfect
To graph the polygon, notice that the vertices are A(2,-1), B(-1,2), C(2,3), and D(4,2) Let's also add the line of reflection y=x.
To reflect the triangle in the given line, we will reflect its vertices. Recall that if a point (a,b) is reflected in the line y=x, then its image is (b, a). With this, let's reflect each vertex of the triangle.
&ABCD && A'B'C'D'
& A(2,-1) && A'(-1,2)
& B(-1,2) && B'(2,-1)
& C(2,3) && C'(3,2)
& D(4,2) && D'(2,4)
Now that we know the reflected vertices, we can plot them and graph the image.
