# how to make working model for teaching mensuration formulas specifically for 3D figures

Creating a working model for teaching mensuration formulas specifically for 3D figures can be a highly effective teaching tool.

Here’s a comprehensive guide to making a DIY math TLM (Teaching Learning Material) working model that includes various 3D figures and their mensuration formulas.

### Materials Needed

• Cardboard
• Scissors
• Glue or tape
• Ruler
• Compass
• Markers
• String
• Styrofoam (optional)
• Colored paper or felt
• Transparent plastic sheet (optional)
• Small whiteboard or cardboard for writing formulas
• Hot glue gun (optional for stronger bonds)

### 3D Figures to Include

1. Cube
2. Cuboid
3. Cylinder
4. Cone
5. Sphere
6. Pyramid (Square Base)

### Steps to Create Each Model

#### 1. Cube

Materials: Cardboard, markers Formulas: Surface Area (SA) = 6a², Volume (V) = a³

Instructions:

1. Cut out six identical squares from cardboard.
2. Glue the squares together to form a cube.
3. Label each side with the edge length (a).
4. Write the formulas for surface area and volume on a small piece of cardboard and attach it to the model.

#### 2. Cuboid

Materials: Cardboard, markers Formulas: Surface Area (SA) = 2(lb + bh + hl), Volume (V) = lbh

Instructions:

1. Cut out rectangles for each face of the cuboid.
2. Assemble the rectangles to form the cuboid.
3. Label the length (l), breadth (b), and height (h) on the model.
4. Write the formulas for surface area and volume on a small piece of cardboard and attach it to the model.

#### 3. Cylinder

Materials: Cardboard, markers, string Formulas: Surface Area (SA) = 2πr(h + r), Volume (V) = πr²h

Instructions:

1. Use a compass to draw and cut out two circles for the bases.
2. Cut a rectangle for the curved surface with height (h) and width equal to the circumference of the base (2πr).
3. Glue the rectangle to form a cylinder and attach the circles to the top and bottom.
4. Label the radius (r) and height (h).
5. Write the formulas for surface area and volume on a small piece of cardboard and attach it to the model.

#### 4. Cone

Materials: Cardboard, markers, string Formulas: Surface Area (SA) = πr(r + l), Volume (V) = ⅓πr²h

Instructions:

1. Use a compass to draw and cut out a circle for the base.
2. Cut a sector from another circle and roll it to form the cone.
3. Attach the base to the cone.
4. Label the radius (r), height (h), and slant height (l).
5. Write the formulas for surface area and volume on a small piece of cardboard and attach it to the model.

#### 5. Sphere

Materials: Styrofoam ball or cardboard, markers Formulas: Surface Area (SA) = 4πr², Volume (V) = ⅘πr³

Instructions:

1. Use a Styrofoam ball or create a sphere from cardboard.
3. Write the formulas for surface area and volume on a small piece of cardboard and attach it to the model.

#### 6. Pyramid (Square Base)

Materials: Cardboard, markers, string Formulas: Surface Area (SA) = B + ½Pl, Volume (V) = ⅓Bh

Instructions:

1. Cut out a square for the base and four triangles for the sides.
2. Assemble the triangles to form the pyramid and attach them to the base.
3. Label the base side (b), slant height (l), and height (h).
4. Write the formulas for surface area and volume on a small piece of cardboard and attach it to the model.

### Assembly and Presentation

1. Base Board: Use a large cardboard sheet as the base.
• Attach each 3D shape with its corresponding formulas on the base board.
• Arrange the shapes in an organized manner for better visualization.
2. Interactive Elements:
• Use Velcro or magnets to make shapes detachable so students can handle and explore them.
• Add flaps or sliders to cover and reveal formulas for an interactive quiz feature.
3. Formula Display:
• Use a small whiteboard or a piece of cardboard to write and explain the formulas.
• Attach this to the base board for easy reference.
4. Color Coding:
• Use different colors for different shapes to make the model visually appealing and easier to understand.
• Color-code the formulas to match the shapes.