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A diagonal line of a polygon is a line that joins any two vertices not already joined by a side.

A polygon with n sides has n(n-3)/2 diagonals

→ a decagon has 10(10-3)/2 = 10 × 7 ÷ 2 = 35 diagonals

Q: How many diagonal lines does a decagon have?

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A decagon need not have any lines of symmetry. It can also have 1 or 10 lines of symmetry.

A decagon need not have any lines of symmetry. It can have 10.

Ten.

A decagon is a 10 sided polygon Exterior angles add up to 360 degrees Interior angles add up to 1440 degrees It has 35 diagonal A decagon can have a regular or an irregular shape

6

Related questions

A decagon has 35 diagonals

There are 35 diagonals inside a decagon

35 diagonals

A decagon need not have any lines of symmetry. It can also have 1 or 10 lines of symmetry.

A regular decagon would have five sets or parallel lines.

A decagon need not have any lines of symmetry. It can have 10.

10 lines of symmetry

10

A heptagon has 4 diagonal lines and 7 sides and it has 2 congruent diagonal lines and 2 congruent triangles

There are four diagonal lines in a hexagon.

10

The answer is 24.