Question

On the grid below triangle MNP is plotted with vertices at M(-10,-2), N(-6,-9) and P(1,-5). The line y=-2/3x is also drawn.(a) Draw the image of triangle MNP after a reflection in y=-2/3x. Give the coordinates of the transformed vertices below.(b) Explain why triangle M'N'P' must have the same area as triangle MNP.

Answer 1

We have the following:

The reflection is:

$\begin{gathered} M(-10,-2)\rightarrow M^{\prime}(2,10) \\ N(-6,-9)\rightarrow N^{\prime}(9,6) \\ P(1,-5)\rightarrow P^{\prime}(5,-1) \end{gathered}$

a) The graph is:

b)

Since the sides are still the same length, for this reason keep the same area