Solve a Quick Math Question: How Many Sides in a Polygon w/ 119 Diagonals?

  • Thread starter Thread starter get_rekd
  • Start date Start date
AI Thread Summary
To determine the number of sides in a polygon with 119 diagonals, the formula d = n(n-3)/2 is used, where d represents the number of diagonals and n the number of sides. By substituting 119 for d, the equation becomes 119 = n(n-3)/2. This leads to the quadratic equation n^2 - 3n - 238 = 0. Solving this equation using the quadratic formula will yield the value of n, indicating the number of sides in the polygon. The discussion emphasizes the need for assistance in solving this quadratic equation.
get_rekd
Messages
39
Reaction score
0
d=n^2 - 3n / 2

where d = number of diagonals
and n = the number of sides of the polygon.

A polygon has 119 diagonals, how many sides does it have?

119 = n^2 - 3n / 2

I am not sure how to do this? can someone please help?

sorry this isn't physics related
 
Physics news on Phys.org
An n-sided polygon has this many diagonals:

\frac{n(n-3)}{2}

Solve for n.
 
get_rekd said:
d=n^2 - 3n / 2

where d = number of diagonals
and n = the number of sides of the polygon.

A polygon has 119 diagonals, how many sides does it have?

119 = n^2 - 3n / 2

I am not sure how to do this? can someone please help?

sorry this isn't physics related
Quadratic Formula
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Solve for n: 119 = n^2 - 3n / 2
Replies
2
Views
2K
Questions about a habitable second moon
Replies
37
Views
6K
Focussing a collimated beam using a diffraction grating
Replies
1
Views
661
Interior and Exterior Angle of a Polygon: Formula not working
Replies
3
Views
2K
Find the number of diagonals that can be drawn in an n-side polygon
Replies
3
Views
2K
Calculating Diagonals of a Polygon: What are the Values of p and q?
Replies
17
Views
3K
Perimeter relationships -- Dividing a rectangle into 4 triangles
Replies
2
Views
2K
Curiosity Question 1: Compression force from tension
Replies
11
Views
3K
Proving convergence of rational sequence
Replies
2
Views
1K
How many times will the block cross the rough patch
Replies
10
Views
3K

Hot Threads

Recent Insights

Back
Top