# Surface area Class 9 Maths Telugu Medium For all Competitive exams

You are going to learn about the chapter called surface area, this topic is taken from the class 9th it mostly explains the surface of a product and their shapes. From this topic mostly they ask for the competitive exams. Here we are going to know what they are.

## Text contents only for the surface area

• Surface area of a cuboid and a cube
• Surface area of a right circular
• Surface area of a right circular cone

### Surface area of a cuboid and a cube

If the cuboid has length l, breadth b, and height h,
Perimeter Of Cuboid = 4(l + b + h), the surface area of the cuboid = 2(lb+bh+lh),Lateral surface area of the cuboid = 2(l+b)xh, Volume of the Cuboid = lbh

If the length of each edge of a cube is l, then the perimeter of the cube=121=12 (edge)2, the surface area of the cube= 6 I2= (edge)2, Lateral surface area of the cube = 4l2 =4(edge)2.
Example for the understanding rest of the questions u will get in text

Q Find the lateral surface of an area and total surface area of the cuboid of length 80 cm, breadth 40 cm, and height 20 cm.

Solution:- Length of the cuboid (l) = 80 cm, Breadth (b) =40 cm, Hight (h)= 20 cm
i) ∴ Lateral surface of an area = 2h(l + b)
=2 x 20(80 + 40) cm² = 40 x 120 = 4800 cm²
(ii)The total surface area is = 2(lb+bh+hl)
= 2(80 x 40 + 40 x 20 + 20 x 80) cm² = 2(3200 + 800 + 1600) cm² = 5600 x 2 = 11200 cm²

## Surface area of a right circular

Let us discuss the right circular cylinder properties. If the line joining to the center of the circle is called the axis. When we are revolvet a rectangle about one side then the axis of revolution takes place, then the right cylinder is formed.

The section is obtained on cutting a right circular cylinder by the plan, which contains two elements, and the parallels to the cylinder are known as a rectangle. Then if the plane cuts the right cylinder horizontally it is parallel to the bases, then it is called a circle

Example for the understanding rest of the questions u will get in text Q Find the volume of a right cylinder if the radius and the height of a cylinder are 20 cm and 30 cm respectively.

Solution: We know,
The volume of a right cylinder is = πr2 h cubic units
Given is the r = 20 cm h = 30 cm
Therefore, using the formula, we get;
Volume = 3.14 × 202 × 30
= 3.14 × 20 × 20 × 30
= 37680
The volume of a given right cylinder is the = 37680 cm3

### Surface area of a right circular cone

If the r, h, and l are denoted respectively to the radios of base, height, and slant height of a right circular cone, then:

#### Conclusion

These types of questions are asked in the exams. Make a practice of these questions. for the competitive exams, and after completing the task, now you have a deep knowledge surface area chapter to make showers fulfill your dreams.