Please help (Look at picture)

How can we find the measure of an exterior angle if we know the measurement of an interior angle

Find the value of a. the diagram is not to scale. a quadrilateral is drawn. the upper and lower sides are parallel. the interior angle in the upper left corner is labeled a degrees. the angle in the upper right corner is labeled 113 degrees. the angle in the lower right corner is labeled b degrees. the angle in the lower left corner is labeled 36 degrees. a. 36 b. 144 c. 54 d. 126

Acredit card advertises an annual interest rate of 23%. what is the equivalent monthly interest rate?