Question

The measure of two adjacent angles of a parallelogram are in the ratio 4 :5. the measure of each of the angle of the parallelogram is 60 degree to 120 degree, 40 to 140 degree, 80 to 100 degree, 100 to 125 degree

Answer 1

Let the angles be 4x and 5x respectively.

4x+5x= 180° (Sum of adjacent angles of a parallelogram is 180°)

9x = 180°

x= 180/9

x= 20°

1st angle = 4x = 4×20 = 80°

2nd angle = 5x = 5×20 = 100°

3rd angle = 80 (Opposite angles of a parallelogram are equal.)

4th angle = 100 (Opposite angles of a parallelogram are equal.)

So option c) 80 to 100 degree.