Mathematics

If $M$ and $N$ are the points $(-3,8)$ and $(5,-7)$ respectively, find $MN$.

Each interior angle of a regular polygon is 168°. Find the number of sides of the polygon.

Find the number of sides of a regular polygon whose interior angle is twice the exterior angle.

Evaluate correct to two decimal places, 75.0785 - 34.624 + 9.83