๐Ÿงฎ Introduction

In this chapter, we study surface area and volume of 3D shapes such as:

  • Cube

  • Cuboid

  • Sphere

  • Hemisphere

  • Cylinder

  • Cone

  • Frustum of Cone

It helps us calculate space occupied or area covered by these solids in real-life scenarios like tanks, pipes, ice cream cones, and more.


๐Ÿ“ 1. Surface Area & Volume Formulas

SolidSurface Area (TSA)Curved Surface Area (CSA)Volume
Cube6a26a^2a3a^3
Cuboid2(lb+bh+hl)2(lb + bh + hl)l×b×hl \times b \times h
Sphere4ฯ€r24\pi r^243ฯ€r3\frac{4}{3} \pi r^3
Hemisphere3ฯ€r23\pi r^22ฯ€r22\pi r^223ฯ€r3\frac{2}{3} \pi r^3
Cylinder2ฯ€r(h+r)2\pi r(h + r)2ฯ€rh2\pi rhฯ€r2h\pi r^2 h
Coneฯ€r(l+r)\pi r(l + r)ฯ€rl\pi rl13ฯ€r2h\frac{1}{3} \pi r^2 h
Frustumฯ€(r1+r2)l+ฯ€r12+ฯ€r22\pi (r_1 + r_2)l + \pi r_1^2 + \pi r_2^2ฯ€(r1+r2)l\pi (r_1 + r_2)l13ฯ€h(r12+r22+r1r2)\frac{1}{3} \pi h (r_1^2 + r_2^2 + r_1r_2)

๐Ÿง  Where:

  • aa: edge of cube

  • rr: radius

  • hh: height

  • ll: slant height (cone/cylinder)

  • r1,r2r_1, r_2: radii of frustum ends


๐Ÿ“ 2. Conversions

  • 1 cm = 0.01 m

  • 1 m³ = 1000 liters

  • Surface area is measured in cm², m²

  • Volume is measured in cm³, m³ or liters


๐Ÿง  3. Tips to Remember

  • For hollow shapes, subtract inner volume from outer volume.

  • For composite solids, calculate each part separately and then add/subtract accordingly.

  • Use ฯ€ = 3.14 or 22/7 as required.


๐ŸŽฏ 4. Real-Life Applications

  • Water tanks, containers, packaging

  • Conical tents, ice cream cones

  • Cylindrical pipes, gas cylinders


✍️ 5. Example Problems

Q1. A cylinder has radius 7 cm and height 10 cm. Find its total surface area.

TSA=2ฯ€r(h+r)=2×227×7(10+7)=2×22×17=748 cm2\text{TSA} = 2\pi r(h + r) = 2 \times \frac{22}{7} \times 7 (10 + 7) = 2 \times 22 \times 17 = 748 \text{ cm}^2

Q2. A cone has radius 3.5 cm and slant height 10 cm. Find its curved surface area.

CSA=ฯ€rl=227×3.5×10=110 cm2\text{CSA} = \pi r l = \frac{22}{7} \times 3.5 \times 10 = 110 \text{ cm}^2

✅ Key Takeaways

  • Always understand shape and formula before applying.

  • Use correct units: cm², m², cm³, liters, etc.

  • Practice composite solids questions for higher-level exams.


๐Ÿ“Œ Summary Table

ShapeCurved Surface AreaVolume
Coneฯ€rl\pi rl13ฯ€r2h\frac{1}{3} \pi r^2 h
Sphere43ฯ€r3\frac{4}{3} \pi r^3
Frustumฯ€(r1+r2)l\pi (r_1 + r_2)l13ฯ€h(r12+r22+r1r2)\frac{1}{3} \pi h (r_1^2 + r_2^2 + r_1r_2)

๐Ÿ“ฅ Download Chapter 16 PDF Notes(Coming Soon)
๐Ÿงฎ View all Class 10 Maths Chapters: Click here »
๐Ÿ”” Bookmark ToppersNoteHub for full Maths + Science notes & updates