Skip to lesson

Math · Pre-K Math

Chapter 3: Shapes All Around

Triangles

Three sides, three corners.

Lesson
2
Time
About 6 minutes
0 of 5 done

Step 1: Let's Learn

Read it, or press Listen and follow the words.

A triangle has three straight sides and three corners. Always three of each.

Count the corners to check

Corners are easier to count than sides, because they are points you can put a finger on.

They can look very different

Tall thin ones, wide flat ones, pointy ones, ones lying on their side. All triangles.

Only the three matters

Size does not matter. Colour does not matter. Which way up it is does not matter. Three straight sides makes it a triangle.

What is not a triangle

If one side curves, it is not a triangle. Straight means straight all the way.

Step 2: Try It Yourself

Tap and try it out.

Turn the triangle. Count the sides.

Triangle

Straight sides

3

Corners

3

A triangle has 3 straight sides.

Turning it does not change what it is.

Step 3: Watch an Example

One step at a time.

Watch Bo Count Sides

Bo looks at a slice of pizza.

  1. Step 1

    He runs his finger along one straight edge.

Step 4: Your Turn

Practice makes it stick.

The Roof

Problem 1 of 1

A shape has three sides. What is it?

Three Sides

1 of 3

How many sides does a triangle have?

2 of 3

How many corners does a triangle have?

3 of 3

Which has more sides, a triangle or a square?

Step 5: Quick Check

Show what you know.

Question 1 of 1

How many corners does a triangle have?

What You Learned

  • A triangle has three straight sides.
  • It has three corners too.
  • Triangles come in many shapes.