Question

Naming an Image
On a coordinate plane, triangle D E F is reflected across the x-axis to form another triangle.

In the graph, the triangle on the top is the pre-image.

Which is the correct name for the image?
TriangleD'E'F'
TriangleDEF
TriangleDEF'
TriangleFED

Answer 1

Triangle D'E'F'

When a figure is reflected, each vertex is labeled with a prime to show its image (D → D', E → E', F → F'), so the image is triangle D'E'F'.