Question

d. can a parallelogram be constructed with exactly three right angles?
a. yes, it is possible.
b. no, it is not possible. the fourth angle must be an obtuse angle
c. no, it is not possible. the fourth angle must be an acute angle.
d. no, it is not possible. the fourth angle must also be a right angle

Explanation:

The sum of the interior angles of a quadrilateral (a parallelogram is a type of quadrilateral) is 360 degrees. If three angles are right - angles (each 90 degrees), then the sum of those three angles is 270 degrees. So the fourth angle is 360 - 270=90 degrees. A parallelogram with four right - angles is a rectangle (a special parallelogram), but it's not possible to have exactly three right - angles in a parallelogram.

Answer:

D. No, it is not possible. The fourth angle must also be a right angle