What is the name of a polygon whose angles add up to 9900 degrees?
How many sides does a polygon have if it has 1175 diagonals?
PS:This isn't my homework. It's a test review packet. My teacher won't help me because a class already took the test.
2007-01-17 12:02:42 · 5 answers · asked by hop333000 2 in Science & Mathematics ➔ Mathematics
The sum of the interior angles of a simple n-gon (n−2)180 degrees.
Read this for the second question:
http://mathforum.org/library/drmath/sets/select/dm_polygon_diagonals.html
2007-01-17 12:11:08 · answer #1 · answered by Jerry P 6 · 0⤊ 0⤋
S = 180(n-2)
9900 = 180 n - 360
10260=180n
n = 57 sides
I would call it a 57-gon
d = n(n-3)/2
1175*2 = n^2-3n
n^2-3n - 2350 = 0
n = [3 +/- sqrt(9 +4*2350)]/2
n = 3/2 +97/2 = 100/2 = 50 sides
2007-01-17 22:06:23 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋
1)
9900 = (n-2)180
55 = n-2
57=n
57-gon
2)
1175 = n(n-3)/2
2350=n(n-3)
0=n2-3n-2350
Sorry i dont have a calculator to do the factoring for the last one, but thats the best i can do!
2007-01-17 20:18:40 · answer #3 · answered by Nabiha... 4 · 0⤊ 0⤋
for INTERIOR angles (which i think your talking about), the formula is this:
(n-2)(180)=d
d=sum of interior angles
n=number of sides
n-2)(180)=9900
n-2=55
n=57
a fifty-seven o gon maybe?
second one...
the number of corners is the same as the number of sides.
diagonals=number of corners-3 (can't connect to itself or its neighboring corners to count as a diagonal)
so 1178
2007-01-17 20:12:46 · answer #4 · answered by Spearfish 5 · 0⤊ 0⤋
ur on ur own mate...
2007-01-17 20:07:16 · answer #5 · answered by chaingang325 2 · 0⤊ 0⤋