What Are Congruent Shapes?

      Congruent shapes have the exact same shape and size.

Of the shapes below, only the triangles are congruent.

      If you put two congruent shapes on top of each other, the top one completely covers the bottom one.

Tip: congruent shapes can have different colors.

To test if two shapes are congruent, they need to have:

✅ the same shape

✅ the same size

Are These Shapes Congruent?

Let's check.

(1) Are they the same shape?

✅ Yes, they're the same shape, a circle.

(2) Are they the same size?

One circle is big. The other one is smaller than it.

❎ No, they're not the same size.

👉 These shapes are not congruent.

Example 2

Are these congruent?

Let's check!

(1) Are they the same shape?

One shape has 5 sides. The other shape has 8 sides.

❎ No, they're not the same shape.

(2) Are they the same size?

❎ No, they're not the same size.

This pair does not check out on the two tests.

👉 These shapes are not congruent.

Example 3

(1) Are these triangles the same shape?

✅ Yes, they're the same shape, a triangle.

(2) Are they the same size?

✅ Yes, they're the same size.

👉 These two shapes are congruent! 😃

Their colors are different.

Are they still congruent?

Yes, because color doesn't matter when looking for congruence.

The triangles are congruent because they have the same shape and size.

Example 4

Are these congruent? 🤔

It might seem like they're not.

But let's check.

(1) Are they the same shape?

✅ Yes, they're both triangles. They are the same kind of triangle.

Their sides and angles are the same.

(2) Are they the same size?

It's tough to tell.

What if we rotate it to the right?

Like this:

Do their sizes look the same now?

✅ Yes, they have the same size! 

This means that these triangles are congruent.

Tip: Congruent shapes match even if you flip, slide, or turn them.

Great job learning about congruent shapes!

Now, ace the practice. 💪 It'll help you remember what congruent shapes are for longer.