A. The sum of the measures of the interior angles of the decagon is 1440 degrees.
Explanation: The sum of interior angles in any polygon can be found using the formula (n-2) * 180, where n is the number of sides. For a decagon (10 sides), it would be (10-2) * 180 = 1440 degrees.
B. The measure of each interior angle will be 144 degrees, and each exterior angle will be 36 degrees.
Explanation: In a regular polygon, each interior angle is equal, so dividing the sum by the number of sides gives the measure of each angle. For a decagon, it's 1440 / 10 = 144 degrees. The exterior angle is supplementary to the interior angle, so it's 180 - 144 = 36 degrees.
C. The sum of all ten exterior angles will be 360 degrees.
Explanation: In any polygon, the sum of all exterior angles is always 360 degrees. Each exterior angle in this decagon is 36 degrees, and 36 * 10 = 360 degrees.