# Class 7 Maths Chapter 6 Exercise 6.3 Pdf Notes NCERT Solutions

Class 7 Maths Chapter 6 The Triangles And Its Properties Exercise 6.3 pdf notes:-

Exercise 6.3 Class 7 maths Chapter 6 Pdf Notes:-

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## Ncert Solution for Class 7 Maths Chapter 6 The Triangles And Its Properties Exercise 6.3 Tips:

ANGLE SUM PROPERTY OF A TRIANGLE
There is a remarkable property connecting the three angles of a triangle. You are going to
see this through the following four activities.

1. Draw a triangle. Cut on the three angles. Rearrange them as shown in.
The three angles now constitute one angle. This angle is a straight angle and so has
measure 180Ā°.
Fig 6.13
Thus, the sum of the measures of the three angles of a triangle is 180Ā°.
2. The same fact you can observe in a different way also. Take three copies of any
triangle, say āABC
3. Take a piece of paper and cut out a triangle, say, āABC.Make the altitude AM by folding āABC such that it passes through A.Fold now the three corners such that all the three vertices A, B and C touch at M.You find that all the three angles form together a straight angle. This again shows thatthe sum of the measures of the three angles of a triangle is 180Ā°.
4. Draw any three triangles, say āABC, āPQR and āXYZ in your notebook.Use your protractor and measure each of the angles of these triangles.Tabulate your resultsName of ā Measures of Angles Sum of the Measuresof the three AnglesāABC mā A = mā B = mā C = mā A + mā B + mā C =āPQR mā P = mā Q = mā R = mā P + mā Q + mā R =āXYZ mā X = mā Y = mā Z = mā X + mā Y + mā Z =Allowing marginal errors in measurement, you will find that the last column alwaysgives 180Ā° (or nearly 180Ā°).When perfect precision is possible, this will also show that the sum of the measures ofthe three angles of a triangle is 180Ā°.You are now ready to give a formal justification of your assertion through logicalargument.Statement The total measure ofthe three angles of atriangle is 180Ā°.To justify this let us use the exteriorangle property of a triangle.