“The camping (a)   is like a pyramid,” Olivia says.

What other objects are pyramids?

A pyramid is a (a)   (có hình tam giác) 3-D shape.

There are two common kinds.

One kind has four (a)   (cạnh)

It’s sometimes called the triangle pyramid.

All four sides are triangles.

At least three sides are always the .... ..... (có cùng kích thước)

(a)  

Some games have four-sided (a)   (xúc xắc)

They are triangle pyramids.

The other kind has five sides.

It’s also known as the (a)   (vuông) pyramid.

This shape has four triangular sides.

They are always the same size.

The ..... .... (mặt thứ 5) is a square.

(a)  

In real buildings, it’s usually the (a)   (đáy)

The Egyptian pyramids are examples.

What other 3-D shapes do you know?