Slice a cone through the top, up and down

Step by step

The question

Question: what shape is the cut, if we slice a cone through the top, up and down?

A cross section is the flat face we see when we slice a solid.

1 Look at the cut

Here is the cone.

We slice it through the top, up and down.

The red face is the cut.

2 Name the shape

Flat, the cut looks like this.

Up and down through the top: the cut is a triangle, as wide as the base, as tall as the cone.

So it is a triangle.

Careful!

Not a circle.

Only a cut straight across shows the round part.

3 Check

Let's check: look at the cone from the side.

You see a triangle, the same as the cut through the middle.

So the answer is right!

Let's look back.

First: look at the cut.

Then: name the shape.

Last: check.