Triangle is present in dodecagon: We use following formula for evaluation of how many Triangles are present in dodecagon.

Triangles are present in dodecagon = n – 2, here 'n' is equal to sides

= 7 – 2,

= 5,

So, there are total 5 triangles are present in dodecagon.

Interior angle of dodecagon – we use following formula for evaluation of interior angle of dodecagon -

(180 * n – 360) / n,

=> (180 * 12 – 360) / 12,

= > 175 degree,

So, interior angle of dodecagon is 175 degree.

Exterior angle of dodecagon: We use following formula for evaluation of exterior angle of dodecagon–

Exterior angle of dodecagon = 180 – interior angle,

=> 180 – 175,

=> 5 degree,

So, exterior angle of dodecagon is 5 degree.

Diagonal of dodecagon: we use following formula for evaluation of diagonal of dodecagon –

Diagonal of dodecagon = (1 / 2) * n * (n – 3), here ‘n’ is number of side,

=> (1 / 2) * 12 * (12 – 3),

=> 6 * (9),

=> 54,

So, total diagonals of dodecagon are 54. Therefore, these are all things explain with 12 sided geometry.