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Triangles
Last updated at November 5, 2025 by Teachoo
Class 7 (Ganita Prakash & Old NCERT)
Chapter 7 Class 7 - A tale of three Intersecting Lines (Ganit Prakash)
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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
- 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
Triangles Triangle is made by joining any 3 non-collinear points. Non-collinear means all 3 points are not in a straight line A triangle has 3 vertices − A, B, C 3 sides − AB, BC, AC 3 angles − ∠A, ∠B, ∠C Interior and Exterior of a Triangle Here, P, Q are in interior of ∆ABC R is on triangle ∆ABC X, Y are in exterior of ∆ABC
