Putting Two Shapes Together to Make a Brand New Shape

Look for this idea outside of your lessons. Quilts, tiled floors, and mosaic windows are all composite shapes made from small pieces fitted together. This is worth learning because most real objects are made of simple shapes joined together. Watch for it today, and when you spot it, tell someone what you noticed and how you knew. Ask yourself where else the same idea might be hiding, then go and look.

Let us look at this together. Shapes combine. Two triangles with matching sides can form a square or a larger triangle. Two squares side by side make a rectangle.

Six triangles arranged around a point make a hexagon. Try it with pattern blocks and notice which shapes fit and which leave gaps. The new shape is called a composite shape, which just means made of parts, and the parts are still inside it.

Try this one. Fit two triangles together along their longest sides and see what you get. Then try along a shorter side. Different joins give different shapes, and discovering that is more valuable than being told it. Say it out loud once, and then try it with real objects.