Question

Number of diogonals of pentagon is​

Answer 1

Correct question:

Number of diagonals in a pentagon is/are _______.

Answer:

Number of diagonals in a pentagon are 5 (five).

___________________

⭐MORE TO KNOW

___________________

How can we find the number of diagonals in a polygon?

Use this formula ⇒ $\frac{n(n-3)}{2}$

Where n is the number of sides of the given polygon.

Let's understand this by taking up a few examples!

• Pentagon - We know that a pentagon has 5 sides, so n = 5.

Number of diagonals = $\frac{5(5-3)}{2}$

                                    = $\frac{5*2}{2}$

                                    = $\frac{10}{2}$ = 5

Therefore a pentagon has 5 diagonals.

• Hexagon - We know that a hexagon has 6 sides, so n = 6.

Number of diagonals = $\frac{6(6-3)}{2}$

                                    = $\frac{6*3}{2}$

                                    = $\frac{18}{2}$ = 9

Therefore a hexagon has 9 diagonals.

• Octagon - We know that a hexagon has 8 sides, so n = 8.

Number of diagonals = $\frac{8(8-3)}{2}$

                                   = $\frac{8*5}{2}$

                                   = $\frac{40}{2}$ = 20

Therefore an octagon has 20 diagonals.

Answer 2

Answer:

5

Step-by-step explanation:

The diagonals of any poygon can be calculated using the formula n×(n−3) /2,where n is the number of sides, in case of a pentagon "n" will be 5.

5(5-3)/2

=5