Question

A shape has 19 sides which are not congruent. The measure of 18 combined interior angles measure 2,940 degrees. What is the measure of the remaining interior angle?

- 140 degrees
- 80 degrees
- 120 degrees
- 60 degrees​

Answer 1

Explanation:

Start with the given information: The measure of 18 combined interior angles is 2,940 degrees.

2. Calculate the sum of all interior angles in the shape using the formula: sum = (n-2) * 180.

sum = (19-2) * 180

sum = 17 * 180

sum = 3,060 degrees

3. Subtract the sum of the given interior angles from the sum of all interior angles to find the measure of the remaining interior angle:

remaining angle = sum - (measure of the 18 given interior angles)

remaining angle = 3,060 - 2,940

remaining angle = 120 degrees