Every interior angle of a regular octagon is 135°. Find the exterior angle of the octagon.

The number of diagonals in a hexagon is :

If  $$(x_1, y_1)$$​ is the solution of the pair of equations: $$\frac{x}{10} + \frac{y}{5} - 1 = 0$$​ and$$\quad \frac{x}{8} + \frac{y}{6} = 15 \\$$ 
and $$y_1 = \lambda x_1 + 5,$$​ then the value of $$\lambda$$​ is:

The number of real solutions of the equation x² − 3|x| + 2 = 0 is:

The interior angles of a polygon are in arithmetic progression. The smallest angle is 120° and the common difference is 5°. Find the number of sides of the polygon.

For a regular polygon, the sum of the interior angles is 250% more than the sum of its exterior angles. Each interior angle of the polygon measures x°. What is the value of x?

The difference between an interior angle and an exterior angle of a regular polygon is 140°. Find the number of sides of the polygon.​

For a regular polygon, the sum of the interior angles is 300% more than the sum of its exterior angles. Each interior angle of the polygon measures x°. What is the value of x?​

The number of diagonals in a regular heptagon is:

If the difference between the exterior and the interior angles of a regular polygon is 60^o, with an interior angle being greater than the corresponding exterior angle, then find the number of sides of the polygon.