Common Core: 8th Grade Math : Understand Congruency of Two-Dimensional Figures: CCSS.Math.Content.8.G.A.2
Study concepts, example questions & explanations for Common Core: 8th Grade Math
All Common Core: 8th Grade Math Resources
Example Questions
Example Question #45 : Geometry
Are the two shapes shown in the coordinate plane congruent? If so, what transformation did the red shape undergo from the orange shape?
Yes, 
Yes, refection over the x-axis
Yes, translation down
No
No
In order to solve this problem, we first need to know what "congruent" means. For two shapes to be congruent, they need to be the same shape and the same size. The shape can go through a transformation—rotation, translation, or reflection—but nothing else about the original shape can be changed for two shapes to be congruent.
Also, let's recall the types of transformations:
Rotation: A rotation means turning an image, shape, line, etc. around a central point.
Translation: A translation means moving or sliding an image, shape, line, etc. over a plane.
Reflection: A reflection mean flipping an image, shape, line, etc. over a central line.
For this question, we can tell that the triangles are not the same size, the red triangle is narrower; thus, the triangles are not congruent.
Example Question #11 : Understand Congruency Of Two Dimensional Figures: Ccss.Math.Content.8.G.A.2
Are the two shapes shown in the coordinate plane congruent? If so, what transformation did the red shape undergo from the orange shape?
Yes, refection over the x-axis
Yes, translation down and to the left
Yes, 
No
No
In order to solve this problem, we first need to know what "congruent" means. For two shapes to be congruent, they need to be the same shape and the same size. The shape can go through a transformation—rotation, translation, or reflection—but nothing else about the original shape can be changed for two shapes to be congruent.
Also, let's recall the types of transformations:
Rotation: A rotation means turning an image, shape, line, etc. around a central point.
Translation: A translation means moving or sliding an image, shape, line, etc. over a plane.
Reflection: A reflection mean flipping an image, shape, line, etc. over a central line.
For this question, we can tell that the triangles are not the same size, the red triangle is narrower; thus, the triangles are not congruent.
All Common Core: 8th Grade Math Resources
