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It is an octagon with 8 sides.
Let n be the number of sides = number of vertices.
Then each vertex can be connected to n-3 other vertices, giving n(n -3) connections. However, this counts each vertex pair connection twice, so there are:
n(n - 3) / 2 diagonals.
Thus if there are 20 diagonals:
n(n - 3) / 2 = 20
n2 - 3n = 40
n2 - 3n - 40 = 0
(n + 5)(n - 8) = 0
so n = -5 or 8. As a polygon cannot have a negative number of sides, n = 8.
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X plus 20 plus 10x equals 20 plus 9x x equals?
x + 20 + 10x = 20 + 9x 11x + 20 = 20 + 9x Subtract 20 from both sides: 11x = 9x Subtract 9x from both sides: 2x = 0 Divide both sides by 2: x = 0
How do you solve the equation -3x minus 5 equals -20?
Add 5 to both sides of the equation to get rid of the - 5. -3x - 5 + 5 = -20 + 5 Solve and simplify. -3x = -15 Divide both sides of the equation by -3. x = 5
What is the value of x when 3x-5 equals 20?
3x - 5 = 20 Add '5' tp bpth sides 3x = 25 Divide both sides by ;3;/ x = 25/3 = 8 1/3 = 8.333.....
-2x - 14 equals 26?
- 2x - 14 = 26 Switch all signs: 2x + 14 = - 26 Subtract 14 from both sides: 2x = -26 - 14 = - 40 Divide both sides by 2: x = - 40/2 = - 20
What are the names of the shapes?
The names of common 2-dimensional geometrical shapes:No straight sidescircle (constant diameter)ellipse, oval (varying width)Three or more straight lines (polygons) --3 sidestriangle4 sides (quadrilaterals)square (4 equal sides, right angles)trapezoid (4 sides with only 1 set of parallel lines)rectangle (4 sides with 2 sets of parallel lines)rhombus (4 sides, 2 parallel pair)5 sides - pentagon6 sides - hexagon7 sides - heptagon (rarely septagon)8 sides - octagon9 sides - enneagon (classically - nonagon)10 sides - decagon11 sides - hendecagon (classically - undecagon)12 sides - dodecagon (classically - duodecagon)13 sides - tridecagon or triskaidecagon14 sides - tetradecagon15 sides - pentadecagon16 sides - hexadecagon17 sides - heptadecagon18 sides - octadecagon19 sides - enneadecagon (nonadecagon)20 sides - icosagon30 sides - tricontagon1000 sides - chiliagon10000 sides - myriagon1000000 sides - megagonThe names of some 3-dimensional shapes (solids)sphere - 3-dimensional circlespheroid, ellipsoid - 3-dimensional curved shape with oval cross sectionscylinder - circle/oval extended in one direction, with 2 spheroid endscone - circular base, constant triangular cross section-(created by rotating a triangle about a bisector)spiral a flat curvehelix a risen curveShapes with flat planar sides (polyhedrons, polyhedra) --pyramid - solid with 3 or more triangular faces, any number of sides for a basetetrahedron - four triangular facespentahedron - 5 faces (square pyramid, prism)cube - 3-dimensional square, 6 faces
How many diagonals does a 20-sides polygon have?
A polygon with n sides had n*(n-3)/2 diagonals. So a 20 sided polygon would have 20*17/3 = 170
How many sides a polygon with 170 diagonals?
20 sides 1/2*(202-60) = 170 diagonals
What is the total number of diagonals in a polygon with eight sides?
It has 20 diagonals
How many diagonals does a convex polygon with 23 sides have?
A polygon with n sides has n*(n - 3)/2 diagonals. So n = 23 gives 23*20/10 = 230 diagonals
How many sides a polygon has with 10 diagonals?
Such a polygon does not exist. A polygon with n sides has 0.5*n*(n-3) diagonals If there are 10 diagonals then 0.5*n*(n-3) = 10 which requires n2 - 3n - 20 = 0 which has no integer roots.
How many diagonals are in a 20 sided polygon?
There are 170 diagonals
How many diagonals does a 20 gon has?
A 20 sided polygon has 170 diagonals
What type of polygon has 20 diagonals?
A regular octogon (8 sides) has 20 diagonals. An irregular octogon also has 20 diagonals, but only if all its points point outwards.
How many sides and diagonals are there in an octagon?
Sides: 8 Diagonals : 20
How many Diagonals in a 20 sided polygon?
170
How many diagonals does a 12 sided polygon have?
20
How many diagonals can be drawn from any vertex of a 20-sided polygon?
It is 18 diagonals
