### Lesson: Surface Area of Solids Recap

#### Introduction

Understanding how to calculate the surface area of three-dimensional shapes is a crucial aspect of geometry, especially when dealing with real-world objects and structures. Whether it’s for designing an object, painting a room, or packaging a product, knowing how to determine the surface area is invaluable. In this lesson, we’ll revisit the methods for calculating the surface area of various solids, including cubes, cylinders, and spheres, and use 3D modeling tools to aid in visualization and calculation.

#### Objectives

- Review the formulas and methods for calculating the surface area of common three-dimensional shapes.
- Apply these methods to solve practical problems.
- Utilize 3D modeling tools for better visualization and understanding of surface area calculations.

#### Calculating Surface Area of Solids

**Cubes and Rectangular Prisms**:- Surface area of a cube: $6×side_{2}$.
- Surface area of a rectangular prism: $2(lw+lh+wh)$, where $l$ is length, $w$ is width, and $h$ is height.

**Cylinders**:- Surface area: $2πr(h+r)$, where $r$ is the radius of the base and $h$ is the height.

**Spheres**:- Surface area: $4πr_{2}$, where $r$ is the radius.

**Pyramids and Cones**:- Formulas vary based on the shape of the base and slant height.

#### Using 3D Modeling Tools

3D modeling tools provide a dynamic way to explore and calculate the surface area of different shapes:

**GeoGebra 3D Calculator**(GeoGebra):- Allows you to create and manipulate 3D shapes.
- Visualize the different faces that contribute to the total surface area.

**SketchUp**(SketchUp):- More advanced tool useful for creating detailed 3D models.
- Explore how changes in dimensions affect the surface area.

#### Exercise

**Surface Area Calculation Practice**: Create a variety of 3D shapes using a 3D modeling tool. Calculate their surface area manually and then use the tool’s features to verify your calculations.**Real-World Application**: Identify objects in your environment that resemble these 3D shapes. Estimate their surface area and then use 3D modeling tools to create a similar shape and calculate its surface area.

#### Conclusion

Calculating the surface area of solids is a key skill in geometry that has practical applications in numerous fields. By revisiting these calculation methods and using 3D modeling tools for visualization, students can gain a deeper understanding of the concepts and enhance their ability to apply these skills in practical scenarios. Encourage continuous practice and exploration with various shapes to become proficient in surface area calculations.