# Lesson Video: Composing 2D Shapes Mathematics • Kindergarten

In this video, we will learn how to compose simple 2D shapes to make larger shapes.

03:53

### Video Transcript

Composing 2D Shapes

In this video, we will learn how to compose simple 2D shapes to make larger shapes. We could make a rectangle using two triangles. We made or composed a shape using smaller shapes. We made this rectangle using a square and a smaller rectangle. We used two smaller shapes to make a larger shape. We could compose a square using two triangles or four triangles. Let’s practice composing simple 2D shapes to make larger shapes.

Which shape has Victoria made out of triangles?

Victoria has placed two triangles together to make a new shape. What’s the name of the new shape that she made? It’s a rectangle. Victoria has used two triangles to make a rectangle.

Can I make a rectangle by joining these squares together?

If we place our three squares together, have we made a rectangle? Yes, we have. The answer to the question is yes. If we join three squares together, we can make a rectangle.

Daniel is trying to fit triangles into this hexagon. How many triangles will he need in total?

Daniel is trying to make a hexagon using triangles. We have to work out how many triangles he will need. So far, Daniel has used one, two, three, four triangles. How many more triangles do we need to complete the hexagon? We’ve added one more triangle. If we add another, the hexagon is complete. Daniel had already placed four triangles together to make his hexagon. We needed two more triangles to complete it. The total number of triangles that Daniel used is six because four plus two is six. To complete Daniel’s hexagon, he will need six triangles in total.

Which shape has been made using triangles only?

Which of the three shapes has been made using only triangles? The first shape is a triangle. But has it been made from three triangles? No, it hasn’t. And our second shape has been made from two triangles. But it’s also used a rectangle. Our third shape is made from four triangles. The square has been made using only triangles. This is the shape we’re looking for. The square has been made using only triangles.

What have we learned in this video? We’ve learned how to compose 2D shapes to make new shapes.