# A triangle has corners at #(3, 9 )#, ( 7, -2)#, and #( 5, -9 )#. If the triangle is reflected across the x-axis, what will its new centroid be?

##### 1 Answer

Jul 28, 2017

The new coordinates of the centroid is

#### Explanation:

Let the corners of the triangle be

The coordinates of the centroid are

Here, we have

So,

The coordinates of the centroid are

The matrix of the reflection acrossthe x-axis is

Therefore,

The new coordinates of the centroid is