The angles of a quadrilateral are in the ratio 3 : 5 : 7. If the difference between the largest and the smallest of these angles is 76°; find the fourth angle of the quadrilateral.

Three angles of a quadrilateral are in the ratio 4 : 5 : 6. The sum of the least and the greatest of these angles is 160°. Find all the angles of the quadrilateral.

A heptagon has four angles each of 132° and remaining three angles are equal. Find the size of each of the three angles.

Each interior angle of a regular polygon is 144°. Find the interior angle of a regular polygon which has double the number of sides as the first polygon.