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

- Cube
- Cuboid
- Cylinder
- Cone
- Sphere
- Pyramid (Square Base)

### Steps to Create Each Model

#### 1. Cube

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

**Instructions**:

- Cut out six identical squares from cardboard.
- Glue the squares together to form a cube.
- Label each side with the edge length (a).
- 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**:

- Cut out rectangles for each face of the cuboid.
- Assemble the rectangles to form the cuboid.
- Label the length (l), breadth (b), and height (h) on the model.
- 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**:

- Use a compass to draw and cut out two circles for the bases.
- Cut a rectangle for the curved surface with height (h) and width equal to the circumference of the base (2πr).
- Glue the rectangle to form a cylinder and attach the circles to the top and bottom.
- Label the radius (r) and height (h).
- 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**:

- Use a compass to draw and cut out a circle for the base.
- Cut a sector from another circle and roll it to form the cone.
- Attach the base to the cone.
- Label the radius (r), height (h), and slant height (l).

#### 5. Sphere

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

**Instructions**:

- Use a Styrofoam ball or create a sphere from cardboard.
- Label the radius (r).

#### 6. Pyramid (Square Base)

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

**Instructions**:

- Cut out a square for the base and four triangles for the sides.
- Assemble the triangles to form the pyramid and attach them to the base.
- Label the base side (b), slant height (l), and height (h).

### Assembly and Presentation

**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.

**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.

**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.

**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.