# Category: SHAPES AND STRUCTURES

## SHAPES AND STRUCTURES | TRIANGULAR SHAPE | PYRAMIDS AND WEDGES

Some shapes are wider at the bottom than the top. This is called tapering. A tapering shape on its side is a wedge. It can be used to force even giant blocks apart.

# The great pyramids

A pyramid is a shape that has triangular sides meeting in a point. The great pyramids of Giza in Egypt are tombs for kings (pharaohs) that were built by the Ancient Egyptians over 3000 years ago.

The builders of the pyramids found out about strong shapes by trial and error. At first they built a pyramid with steeply sloping sides. They found that this kept falling down.

Having learned this lesson they built pyramids with less steep sides.

# Triangular test

Wedges and pyramids are examples of a triangular shape that can stand up to great forces. It has been used in the design of the skyscraper shown in the picture above.

# Make a door stop

A wedge is a tapering shape that makes a good kind of doorstop. Ask a grown-up to saw a piece of wood to give several wedge shapes like the ones shown below.

Try each wedge in turn to see which one is best at holding a door open. When you have found the one that works best, compare it with a doorstop that can be bought in a shop. Are the shapes similar?

# Opening wedges

Wedges are good at prising things apart because they have a thin blade at one end which changes to a thick blade at the other. You can see a wedge-shape at the end of this chisel. It is used for making a cut in wood.

# INTRODUCTION TO SHAPES AND STRUCTURES

Look at the room you are sitting in. You will see a wide variety of shapes that are strong enough to be pulled, squashed, bent, twisted, hit or dropped.

The walls of your room may be made of building blocks, stacked together. Each block has an oblong or rectangular, shape..

Your body has to be made of strong shapes as well. Feel your arms and legs. They are long and round, similar to rods, or cylinders. Now feel your head. It is round in every direction, roughly ball-shaped or a sphere.

A pyramid was the strong shape the ancient Egyptians used to build their famous burial chambers. Cones are strong shapes, too. Look at the sharp ends of needles, for example.

Our world is exciting because the mix of shapes and materials is almost endless. In this blog you will see a wide variety of interesting shapes. Some are made with everyday materials, others with very special materials. Some of the strongest shapes are made by nature, others by the clever skills of engineers.

Strong shapes are all around you, so there is plenty to look out for. Just turn to next blog posts and start your investigations.