Q. If a pentagon has one angle measuring 120 degrees, what can be inferred about the other angles?
A.
All other angles must also be 120 degrees.
B.
The sum of the other angles must be 360 degrees.
C.
At least one angle must be less than 60 degrees.
D.
The pentagon cannot exist.
Solution
The sum of the interior angles of a pentagon is 540 degrees. If one angle is 120 degrees, the sum of the other four angles must be 540 - 120 = 420 degrees.
Correct Answer:
B
— The sum of the other angles must be 360 degrees.
Q. If a polygon has 10 sides, what is the measure of each interior angle in a regular decagon? (2023)
A.
144 degrees
B.
120 degrees
C.
108 degrees
D.
135 degrees
Solution
The measure of each interior angle in a regular polygon is given by the formula [(n-2) * 180] / n. For a decagon (n=10), it is [(10-2) * 180] / 10 = 144 degrees.
Q. If a polygon has 12 sides, what is the measure of each exterior angle in a regular dodecagon?
A.
30 degrees
B.
36 degrees
C.
15 degrees
D.
45 degrees
Solution
The measure of each exterior angle of a regular polygon can be calculated using the formula 360/n, where n is the number of sides. For a dodecagon (12 sides), it is 360/12 = 30 degrees.
Q. If a polygon has 12 sides, what is the measure of each exterior angle in a regular polygon?
A.
30 degrees
B.
36 degrees
C.
60 degrees
D.
90 degrees
Solution
The measure of each exterior angle of a regular polygon is calculated as 360/n, where n is the number of sides. For a dodecagon (12 sides), it is 360/12 = 30 degrees.
Q. If a polygon has 8 sides, what is the measure of each interior angle in a regular octagon?
A.
135 degrees
B.
120 degrees
C.
108 degrees
D.
150 degrees
Solution
The measure of each interior angle of a regular polygon can be calculated using the formula [(n-2) * 180] / n. For an octagon (n=8), it is [(8-2) * 180] / 8 = 135 degrees.
Q. If a quadrilateral has one angle measuring 120 degrees and the other three angles are equal, what is the measure of each of the equal angles?
A.
30 degrees
B.
40 degrees
C.
60 degrees
D.
80 degrees
Solution
The sum of the angles in a quadrilateral is 360 degrees. If one angle is 120 degrees, the remaining angles must sum to 240 degrees. If the other three angles are equal, each must be 240/3 = 80 degrees.
Q. If angle A and angle B are supplementary, and angle A is 3 times angle B, what is the measure of angle A?
A.
90 degrees
B.
120 degrees
C.
180 degrees
D.
60 degrees
Solution
Let angle B be x. Then angle A = 3x. Since they are supplementary, x + 3x = 180, leading to 4x = 180, so x = 45. Therefore, angle A = 3 * 45 = 135 degrees.
Q. If the angles of a triangle are in the ratio 2:3:4, what is the measure of the largest angle?
A.
60 degrees
B.
80 degrees
C.
90 degrees
D.
120 degrees
Solution
Let the angles be 2x, 3x, and 4x. The sum of angles in a triangle is 180 degrees. Therefore, 2x + 3x + 4x = 180. Solving gives x = 20, so the largest angle is 4x = 80 degrees.