Question

c) Which of the following sets are arrange ay 10 7 3 2 1 () 5 55'5 my ouestion​

Answer 1

Answer:

How many triangles are there in the polygon, from one vertice?

Consider dividing the shape into pieces.

If the polygon is \rm nn -sided, the diagonal we can draw from one vertice is exactly \rm n-3n−3 . We can't connect itself and the adjacent vertices.

The diagonal will divide the triangle into exactly \rm n-2n−2 pieces. This is due to the first diagonal divides the shape into two pieces.

There exist exactly \rm n-2n−2 triangles, and each of them has 180^{\circ}180

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as the sum