Question

Given AJKL with vertices J (2,4), K(-4,-2), and L(-1,0). List the coordinates of the image of AJKL after the given reflection.Reflection: In y = 1Note: Your answers MUST.Be written as an ordered pair with parenthesesContain NO spaces in your answerMost have a comma between the coordinatesJ'K KL

Answer 1

Recall that when we do a reflection around the axis y = 1 (a horizontal line going through the point "1" in the y axis, each point gets reflected at the same distance they have to the y = 1 axis, but on the other side of the line.

So let's start with the point :

J = (2, 4) which is located at 3 units from the line y = 1 and above it. So during a reflection, it will keep the x-value, and chenge its y-value to 3 units BELOW the y=1 axis, leading to: (2 , -2)

Then (2, 4) goes to (2, -2)

Now the point: K = (-4, -2)

This one is located below the y = 1 axis , and 3 units below it, so during a reflection it will go 3 units above the y = 1 axis, and will keep the same x value:

(-4, -2) will go to (-4, 4)

finally the point L = (-1, 0)

This point is located below the y=1 axis in one unit, then its reflection will place it ONE unit above the y=1 axis. and again the x value will be kept intact:

(-1, 0) goes to (-1, 2)

Then we have found the reflection of all three vertices of the triangle.

Look at a reflection around the line y = 1, like if on that line you have a mirror and the points get reflected on the other side of it.

The x value will not change, but the y value will according to how far away from the "mirror" (y = 1 axis) they were initially.