Combining Simple Shapes
Compose simple shapes to form larger shapes (e.g. two triangles make a rectangle)
What a learner can do afterwards
- Join two triangles to make a rectangle or larger triangle
- Use pattern blocks to fill a hexagon outline
- Create a picture or design by combining basic shapes
1 · Read
You know shapes like triangles and squares. Take a rectangle. Cut it from corner to corner. You get two matching triangles. The cut edge is the long edge on each part.
Ben has a six-sided puzzle. It has six matching triangle pieces. They fill it with no gaps. A shape with six straight sides is called a hexagon.
Shapes can make a picture. A triangle on top of a square makes a house. The triangle is the roof. A triangle sail and a long hull make a boat. The hull is the boat's body.
Round edges leave gaps. A circle cannot press flat on a straight edge. That is why a circle cannot fill a rectangle corner.
Try turning a shape around. Sometimes a turned shape fits together better.
Small shapes can join together to make bigger, new shapes.
More to read
Polygons review
Small shapes join into bigger shapes. Two matching triangles from a rectangle cut fit back into their rectangle. Slide them edge to edge with no gaps. The join line hides inside the new shape.
Right angles in shapes (informal definition)
Pattern blocks fill outlines like puzzles. Ben's six-sided puzzle holds six matching triangle pieces with no holes. Two trapezoids can fill the same puzzle too. Try every combo and count the pieces. Filling proves shapes fit together.
9.5: Area and Volume of Geometric Figures and Objects
Joining shapes builds pictures and designs. Four triangles can star around a square. Rows of rectangles can wall a house shape. Plan with small pieces, then build big. Designers compose with shapes daily.
Match and draw arrays
Arrays line shapes into neat rows. Three rows of four squares tile a rectangle. Count rows, then count across, then total the tiles. Rows turn piles into order. Order makes big counts easy.
Explore more
2 · Watch
En anglaisTake it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
18 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.