Answer:A rectangle is a parallelogram with at least one right angle is the best choice ⇒ answer AStep-by-step explanation:* Lets revise the properties of the rectangle# Each two opposite sides are parallel# Each two opposite sides are equal in length# Its two diagonals bisect each other and equal each other# Its four angles are right angles- The parallelogram can be a rectangle if:# Two adjacent sides are perpendicular to each other means one angle of its four angles is a right angle- OR# Its two diagonals are equal in length* Lets solve the problem- We will study the answers to chose the best one# Answer A- A rectangle is a parallelogram with at least one right angle∵ Each tow opposite angles are equal in the rectangle∵ One of the is right angle means its measure is 90°∴ The measure of the opposite angle is also 90°∵ The sum of the measures of the four angles is 360°∴ The sum of the measures of the other two angles is; 360 - (90 + 90) = 180°∵ They are equal to each other (opposite angles)∴ The measure of each one = 180 ÷ 2 = 90°∴ The measure of the four angles are 90°∴ The four angles of the rectangle are right angles* A rectangle is a parallelogram with at least one right angle is the best choice