Fill in the Blanks Complete geometryOnline version Esaldiak bete geometria gaiako hiztegia edo fómulekin by maite Lopez M 1 a ) A triangle is a - sided polygon . The sum of a triangle is . b ) A is a for - sided polygon . The sum of the angles of any quadrilateral is . c ) The sum of the angles of a polygon with n sides , where n is or is ( n - 2 ) . 180º . d ) As the sum of the angles of a regular polygon with n sides is ( n - 2 ) . 180º , and knowing that their are all the same length and their angles are all the same , each angle in a regular polygon is [ ( n - 2 ) . 180º ] / n