Polyhedra and Area Calculations

Mr. Richards reviews grade 6 practice problems on nets and surface area. He explains why a given net cannot form a cube and identifies a triangular prism from another net. The video covers calculating the surface area of polyhedra, comparing nets to form the same prism, analyzing properties of 3D figures, and discussing appropriate units for surface area. Finally, Mr. Richards demonstrates how to find the area of a complex polygon by dividing it into simpler shapes.

What is the main reason the net in problem 1 cannot form a complete cube?

• The squares are not the same size.

• One square cannot be used as a top or bottom.

• It lacks enough squares to form a cube.

• It has too many squares.

Which polyhedron can be formed from a net with two triangles and several rectangles?

• Pyramid

• Rectangular Prism

• Cube

• Triangular Prism

How do you calculate the area of a triangle?

• Base times height

• Base times height divided by 2

• Length times width

• Length times width divided by 2

What is the total surface area of the triangular prism discussed in the lesson?

• 84 square units

• 90 square units

• 72 square units

• 60 square units

Do both nets in question three form the same triangular prism?

• Yes, but only if rearranged.

• No, they have different triangular bases.

• No, they have different rectangles.

• Yes, they have matching triangular bases and rectangles.

Which statement is true about figure A and B?

• Both have more vertices than edges.

• Both are polyhedra.

• Neither has rectangular faces.

• Only one has triangular faces.

Which of the following units can be used for surface area?

• Cubic inches

• Square meters

• Meters

• Liters

How many triangles are used to calculate the area of the complex polygon in question six?

• Four

• Three

• Two

• One

What is the area of the rectangle in the complex polygon?

• 12 square units

• 15 square units

• 18 square units

• 21 square units

What is the total area of the complex polygon discussed in the lesson?

• 36 square units

• 30 square units

• 33 square units

• 39 square units