📘 Three Dimensional Shapes - Page 8 Explanation
📖 Open your textbook page number 8.
This page gives a short revision in At a glance and then starts Exercise 1.
👀 At a Glance
📌 “Dimensions: One-dimensional, two-dimensional and three-dimensional shapes.”
A polygon is a closed shape made with straight sides. Closed means there is no gap in the shape. Examples are triangle, square, pentagon, and hexagon.
Dimensions tell us how a shape is measured. A one-dimensional shape has only length. A two-dimensional shape has length and width. A three-dimensional shape has length, width, and height.
📝 Exercise 1
(1) Select the correct option.
(i) What shape will be formed if carrom pieces are placed one on top of the other?
Options: A) Cuboid B) Cylinder C) Cone D) Cube
A carrom piece is circular and flat. When many circular carrom pieces are placed one on top of the other, they form a shape like a cylinder.
(ii) By which 2 similar shapes is hourglass formed?
Options: A) Cube B) Triangular prism C) Sphere D) Cone
An hourglass looks like two cones joined at their pointed ends. So, it is formed by two similar cones.
(iii) Which of the following shapes is not three-dimensional?
Options: A) square B) Sphere C) Cylinder D) Cone
A square is a flat two-dimensional shape. It has length and width only. A sphere, cylinder, and cone are three-dimensional shapes because they occupy space.
✏️ Exercise 1 - Question 2
📖 Textbook Question:
"Draw three-dimensional figures from the numbers given below and write the names."
In this question, we are given the properties of different three-dimensional shapes. We have to identify the correct shape by carefully reading the number of faces, edges, and vertices.
🟦 (i)
- There are 5 faces.
- There are 5 vertices.
- There are 8 edges.
- One face is square.
- The remaining faces are triangular.
✅ Answer : Square Pyramid
A Square Pyramid has exactly these properties.
- ◼️ 1 Square Face (Base)
- 🔺 4 Triangular Faces
- 📍 5 Vertices
- 📏 8 Edges
Whenever you see one square face and all other faces are triangles, the shape is a Square Pyramid.
⚽ (ii)
- One face is curved.
- No vertices.
- No edges.
✅ Answer : Sphere
A Sphere has only one curved surface. It has no flat faces, no edges and no vertices.
If a shape is completely round like a ball and has no edges and no vertices, then it is a Sphere.
🧊 (iii)
- 6 Faces
- 12 Edges
- 8 Vertices
✅ Answer : Cube
A Cube has
- 🟦 6 Square Faces
- 📏 12 Edges
- 📍 8 Vertices
Whenever you see 6 Faces + 12 Edges + 8 Vertices, think of a Cube.
🥫 (iv)
- 1 Curved Face
- 2 Circular Edges
- 2 Flat Faces
✅ Answer : Cylinder
A Cylinder has
- 🌀 1 Curved Face
- ⭕ 2 Circular Faces
- ⭕ 2 Circular Edges
If a shape has two circular faces and one curved face, it is always a Cylinder.
📋 Final Answers
| Question | Correct Answer |
|---|---|
| (i) | Square Pyramid |
| (ii) | Sphere |
| (iii) | Cube |
| (iv) | Cylinder |
🌟 Page Summary
- ✅ We identified three-dimensional shapes by their faces, edges, and vertices.
- ✅ We learned that each 3D shape has its own unique properties.
- ✅ We solved Exercise 1 using simple observation and logical thinking.
- ✅ Remember the properties of each shape carefully because they help in identifying the correct shape quickly.
📅 Reminder App
✅ Officially on Google Play Store
Safe • Trusted • Secure
🎤 Say:
"Remind me after 5 minutes to do homework"
"Remind me tomorrow at 10 AM about the meeting"
Tap Use Result → Save Reminder
⭐ Quick 🔔 Custom Tones 💾 Backup
Developed by EliteDigitalLabs
Recommended by www.elitetutors.in