Two Congruent Right Triangles

The same two right triangles make a rectangle, a kite, two isosceles triangles and two parallelograms: six different shapes with one identical area.

How it works

1. Take the two red 3-4-5 triangles
2. Fit them into each of the six shape pockets in turn
3. Notice that every shape uses the same two pieces

What students learn

• Congruent shapes are the same shape and size
• Different shapes can have the same area
• How triangles combine to form other shapes

Try these activities

1. Work out the area of each shape from the two triangles
2. Find the perimeter of each shape and compare
3. Name each shape and list its properties

Curriculum fit

In the box

• MDF tray 28 x 26 cm with 6 shape pockets
• Two red acrylic 3-4-5 triangles
• Step-by-step manual

Pairs well with

Area of a Triangle ModelMATH-125Pythagoras Theorem Working ModelMATH-123