Question : If one of the interior angles of a regular polygon is $\frac{15}{16}$ times of one of the interior angles of a regular decagon, then find the number of diagonals of the polygon.

Option 1: 20

Option 2: 14

Option 3: 2

Option 4: 35

Question : The sum of the interior angles of a regular polygon A is 1260 degrees and each interior angle of a regular polygon B is $128 \frac{4}{7}$ degrees. The sum of the number of sides of polygons A and B is:

Option 1: 17

Option 2: 16

Option 3: 19

Option 4: 18

Question : Find the number of diagonals of a regular polygon, whose sum of interior angles is 2700°.

Option 1: 121

Option 2: 119

Option 3: 127

Option 4: 117

Question : The sum of interior angles of a regular polygon is $1440^{\circ}$. The number of sides of the polygon is:

Option 1: 10

Option 2: 12

Option 3: 6

Option 4: 8

Question : If the external angle of a regular polygon is 18°, then the number of diagonals in this polygon is:

Option 1: 180

Option 2: 150

Option 3: 170

Option 4: 140