Answer: the equation to determine the value of n is 5n = 105
Step-by-step explanation:
The measure of angle a is n degrees. The measure of angle b is four times angle a. This means that the measure of angle b would be
b = 4n
The measure of angle c is 75 degrees. Since the sum of the interior angles of a quadrilateral is 180 degrees, then the equation to determine the value of n would be
a + b + c = 180
Therefore,
n + 4n + 75 = 180
5n = 180 - 75
5n = 105
n = 105/5
n = 21
