When learning about polygon you can find the interior or the exterior. The formula that you would use is (n-2)180. The n in the equation stands for the number of sides. Convex is the direction of the angle points outside the shape. Concave is the direction of angle that points inside of shape. For polygons you have to know the sides, name, and the total degrees of an angle.
When learning about parallelograms any angle that is parallel from another has the same measure. If a quadrilateral is a parallelogram, then its consecutive angles are supplementary. When a quadrilateral is a parallelogram, then it diagonals bisect each other. Each diagonal separates the parallelogram into two congruent triangles. If a parallelogram has one right angle, then it has four right angles.