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Example Questions
Example Question #1 : Hexagons
How many diagonals are there in a regular hexagon?
A diagonal is a line segment joining two non-adjacent vertices of a polygon. A regular hexagon has six sides and six vertices. One vertex has three diagonals, so a hexagon would have three diagonals times six vertices, or 18 diagonals. Divide this number by 2 to account for duplicate diagonals between two vertices. The formula for the number of vertices in a polygon is:
where .
Example Question #12 : Geometry
How many diagonals are there in a regular hexagon?
10
9
3
6
18
9
A diagonal connects two non-consecutive vertices of a polygon. A hexagon has six sides. There are 3 diagonals from a single vertex, and there are 6 vertices on a hexagon, which suggests there would be 18 diagonals in a hexagon. However, we must divide by two as half of the diagonals are common to the same vertices. Thus there are 9 unique diagonals in a hexagon. The formula for the number of diagonals of a polygon is:
where n = the number of sides in the polygon.
Thus a pentagon thas 5 diagonals. An octagon has 20 diagonals.
Example Question #251 : Plane Geometry
Regular Hexagon has a diagonal with length 1.
Give the length of diagonal .
The key is to examine in thie figure below:
Each interior angle of a regular hexagon, including , measures , so it can be easily deduced by way of the Isosceles Triangle Theorem that . , so by angle addition,
.
Also, by symmetry,
,
so ,
and is a triangle whose long leg has length .
By the Theorem, , which is the hypotenuse of , has length times that of the long leg, so .
Example Question #1 : Hexagons
Regular Hexagon has a diagonal with length 1.
Give the length of diagonal .
The key is to examine in thie figure below:
Each interior angle of a regular hexagon, including , measures , so it can be easily deduced by way of the Isosceles Triangle Theorem that . , so by angle addition,
.
Also, by symmetry,
,
so ,
and is a triangle whose hypotenuse has length .
By the Theorem, the long leg of has length times that of hypotenuse , so .
Example Question #574 : Geometry
Regular hexagon has side length of 1.
Give the length of diagonal .
The key is to examine in thie figure below:
Each interior angle of a regular hexagon, including , measures , so it can be easily deduced by way of the Isosceles Triangle Theorem that . To find we can subtract from . Thus resulting in:
Also, by symmetry,
,
so .
Therefore, is a triangle whose short leg has length .
The hypotenuse of this triangle measures twice the length of short leg , so .
Example Question #3 : Hexagons
Regular hexagon has side length 1.
Give the length of diagonal .
The key is to examine in thie figure below:
Each interior angle of a regular hexagon, including , measures , so it can be easily deduced by way of the Isosceles Triangle Theorem that . To find we subtract from . Thus resullting in
Also, by symmetry,
,
so ,
and is a triangle whose short leg has length .
The long leg of this triangle measures times the length of short leg , so .
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