Question

How many diagonals are there in a polygons of 30 sides
A,810. B,405. C,202. D,740

Answer 1

Answer:

formula of finding diagonal

$n(n - 3) \div 2$

n= no. of sides

So no. of side = 30

diagonal in polygon

$n(n - 3) \div 2$

$30(30 - 3) \div 2$

$30(27) \div 2$

$30(13.5)$

$405$

So the ans is b 405