How many sides are there in a polygon which has 20 diagonals?
8
Using the formula for diagonals in a polygon n(n-3)/2 = 20, we solve for n = 8.
Similar Questions
- How many triangles can be formed by joining these points?
Important Questions from Permutation and Combination
If Quantity A is the number of ways to assign a number from 1 to 5 without repetition to each of four people, and Quantity B is the number of ways to assign a number from 1 to 5 without repetition to each of 5 people, then which of the following statements is correct with respect to Quantities A and B?
Which of the following muscles regulates the exit of food from the stomach into the small intestine?
There are 9 cups placed on a table arranged in equal number of rows and columns out of which 6 cups contain coffee and 3 cups contain tea. In how many ways can they be arranged so that each row should contain at least one cup of coffee?
In how many different ways can the letters of the word 'OPTICAL' be arranged so that the vowels always come together?
There are $15$ distinct points on a plain sheet of paper. If $4$ of these points are collinear, find the maximum number of triangles that can be drawn using these points.
