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Question 2 - Page 159 - Triangle Inequality & Construction of Circles - Chapter 7 Class 7 - A tale of three Intersecting Lines (Ganit Prakash)
Last updated at November 7, 2025 by Teachoo
Triangle Inequality & Construction of Circles
Class 7 (Ganita Prakash 1, 2 & old NCERT)
Chapter 7 Class 7 - A tale of three Intersecting Lines (Ganit Prakash)
- Definition
- Constructing Equilateral Triangle
- Constructing a Triangle when its Sides are given
- Figure it out - Page 150, 151
- Are Triangles Possible for any Lengths?
- Figure it out - Page 154
- Visualising the Construction of Circles
- Figure it out - Page 156
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Triangle Inequality & Construction of Circles
- Figure it out - Page 159
- Constructing Triangle when 2 Sides and the Included Angle are given
- Constructing Triangle when 2 Angles and the Included Side are given
- Do triangles always exist?
- Sum of angles of a triangle
- Angle Sum Property
- Exterior Angles
- Constructions Related to Altitudes of Triangles
- Figure it out - Page 170, 171
Transcript
Question 2 - Page 159 How will the two circles turn out for a set of lengths that do not satisfy the triangle inequality? Find 3 examples of sets of lengths for which the circles: (a) touch each other at a point, (b) do not intersect. If a set of lengths does not satisfy the inequality, it means the sum of the two smaller sides is not greater than the longest side. This leaves two possibilities: (a) ...touch each other at a point: This happens when the sum of the two smaller lengths is exactly equal to the longest length (Case 1). Example 1: 5 cm, 10 cm, 15 cm (since 5 + 10 = 15) Example 2: 3 cm, 6 cm, 9 cm (since 3 + 6 = 9) Example 3: 7 cm, 7 cm, 14 cm (since 7 + 7 = 14) (b) ...do not intersect: This happens when the sum of the two smaller lengths is less than the longest length (Case 2). Example 1: 3 cm, 4 cm, 8 cm (since 3 + 4 < 8) Example 2: 10 cm, 15 cm, 30 cm (since 10 + 15 < 30) Example 3: 2 cm, 5 cm, 10 cm (since 2 + 5 < 10)
