Class 7 Maths · Part 1 Chapter 7 · CBSE / NCERT
A Tale of Three Intersecting Lines
Triangles. You’ll learn to construct triangles from given sides and angles, check if three lengths can form one, use the 180° angle sum and exterior angle, and draw altitudes.
12 short lessons · about 46 minutes in all
What you’ll learn
- 1Corners, sides and angles of a triangle3 min
- 2Building an equilateral triangle4 min
- 3Building a triangle from three side lengths4 min
- 4Equilateral, isosceles and scalene3 min
- 5Can these lengths make a triangle?4 min
- 6Why the rule works: two circles4 min
- 7Two sides and the angle between them4 min
- 8Two angles and the side between them4 min
- 9Angles of a triangle add to 180 degrees4 min
- 10The exterior angle4 min
- 11The height of a triangle: altitude4 min
- 12Triangles by their angles4 min
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Corners, sides and angles of a triangle · about 3 minutes
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More Class 7 Maths
The other 14 chapters.
PART 1 · CH 1Large Numbers Around Us12 lessonsPART 1 · CH 2Arithmetic Expressions10 lessonsPART 1 · CH 3A Peek Beyond the Point12 lessonsPART 1 · CH 4Expressions Using Letter-Numbers11 lessonsPART 1 · CH 5Parallel and Intersecting Lines10 lessonsPART 1 · CH 6Number Play10 lessonsPART 1 · CH 8Working with Fractions10 lessonsPART 2 · CH 1Geometric Twins12 lessonsPART 2 · CH 2Operations with Integers12 lessonsPART 2 · CH 3Finding Common Ground10 lessonsPART 2 · CH 4Another Peek Beyond the Point10 lessonsPART 2 · CH 5Connecting the Dots…12 lessonsPART 2 · CH 6Constructions and Tilings11 lessonsPART 2 · CH 7Finding the Unknown11 lessons
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