# Are there diagonals in an Heptagon?

Yes. Any polygon with four or more sides has diagonals. However, a triangle does not.

### How many diagonal lines do a heptagon has?

A seven sided figure has 14 diagonals. Each vertices has 4 diagonals (but of course some are shared diagonals). The best thing to do is draw a regular heptagon, draw all the diagonals (lines connecting non-adjacent vertices) in pencil and then go back with a red or blue pen and count the diagonals as you trace each line in the different color. AA

### How do angles of heptagon add up too 900?

If you select one vertex of a heptagon and draw diagonals to all other vertices, you will divide the heptagon into 5 triangles such that the interior angles of the heptagon add up to the same sum as the interior angles of the five triangles. Now the sum of the interior angles of one triangle is 180 degrees. So for 5 triangles you get 5*180 = 900 degrees. In general, the interior angles of a…

### How many diagonals does a 20 sided shape have?

A 20 sided shape has 209 diagonals i worked it out by drawing a table and split it into 4 colunms. I named the first one Name of polygon and the second one Number of sides the next one, Angle at centre and the last one Diagonals. I started with a Triangle which has 3 sides and its angle at centre is 120 degrees but, it doesn't have any diagonals so i put 0. Next…

### How many diagonals are there in a decagon?

A decagon has 35 diagonals. A Nonagon has 27 diagonals. An Octagon has 20 diagonals. A Heptagon has 14 diagonals. A Hexagon has 9 diagonals. A Pentagon has 5 Diagonals. A Square has 2 Diagonals. A triangle has 0 Diagonals. Do you get the point? 0+2+3+4+7+8. Starting with the triangle. you don't need to start with the triangle because it is 0 diagonals and will not count when you add it up anyways. And don't…

### What are the mathematical names of the first ten polygons and their properties?

All polygons have 3 or more sides having exterior angles that add up to 360 degrees and the first 10 can be classed as follows in order of their geometrical names, number of sides, sum of interior angles and number of diagonals:- 1 Triangle: 3 sides, 180 degrees and no diagonals 2 Quadrilateral: 4 sides, 360 degrees and 2 diagonals 3 Pentagon: 5 sides, 540 degrees and 5 diagonals 4 Hexagon: 6 sides, 720 degrees…