Question

Chapter - 11 please tell I don’t understand

Answer 1

Answer:

in this triangle how many heptagon draw a single vertex sum of angle

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Answer 2

Answer:

sum of angles = 900°

Step-by-step explanation:

sum of angles of any polygon of sides n = ( n - 2 ) * 180

In heptagon , there is a 7 sides

So,

( 7 - 2 ) * 180

5*180

900°

No. of triangles in a polygon of n sides = NC3

= n!/ ( 3!*(n-3)! )

In heptagon there are 7 sides

7C3 = 7!/ ( 3!*4!)

= 35

Hence , no of traingles in heptagon= 35