To find the number of diagonals in a decagon, we can use the formula:

Number of diagonals = n(n-3)/2

where n is the number of sides of the polygon.

In this case, a decagon has 10 sides, so we can substitute n = 10 into the formula:

Number of diagonals = 10(10-3)/2
= 10(7)/2
= 70/2
= 35

Therefore, the correct answer is (b) 35.

Question

To find the number of diagonals in a decagon, we can use the formula:

Number of diagonals = n(n-3)/2

where n is the number of sides of the polygon.

In this case, a decagon has 10 sides, so we can substitute n = 10 into the formula:

Number of diagonals = 10(10-3)/2
                   = 10(7)/2
                   = 70/2
                   = 35

Therefore, the correct answer is (b) 35.

Knowee AI · Accepted Answer

To find the number of diagonals in a decagon, we can use the formula:

Number of diagonals = n(n-3)/2

where n is the number of sides of the polygon.

In this case, a decagon has 10 sides, so we can substitute n = 10 into the formula:

Number of diagonals = 10(10-3)/2
                   = 10(7)/2
                   = 70/2
                   = 35

Therefore, the correct answer is (b) 35.

The number of diagonals in a decagon is(a) 30 (b) 35 (c) 45 (d) none of these