Question

The triangle JKL shown on the coordinate grid below is reflected once to map onto triangle J'K'L': Triangle JKL is drawn on a 4 quadrant coordinate grid with vertices J is at 8, 1. K is at 5, 7. L is at 3, 4. If vertex L' is at (−3, 4), what are the coordinates of vertex J'?

Answer 1

The vertex J' is at (-8,1).

Explanation:

If is given that the triangle JKL reflected once to map onto triangle J'K'L'.

The vertices of the triangle JKL are J(8,1), K(5,7) and L(3,4). The vertex L'(-3,4).

`L(3,4)\rightarrow L'(-3,4)`

It is in the form of

`(x,y)\rightarrow (-x,y)`

Since the y-coordinate remains same and the sign of x coordinate is changed. It shows the reflection across the y axis.

The vertices of image are,

`K(5,7)\rightarrow K'(-5,7)`

`J(8,1)\rightarrow J'(-8,1)`

Therefore the vertex J' is at (-8,1).

Answer 2

If vertex L' is at (−3, 4), what are the coordinates of vertex J'?
(1, −8)
(−8, 1)
(−1, 8)
(8, −1)