Question

if one angle of a trapezoid is a right angle, the greatest number of additional angles a trapezoid might have is
select one:
a. 2
b. 3
c. 1

if one angle of a parallelogram is a right angle, the parallelogram is a
select one:
a. rhombus
b. square
c. rectangle

Explanation:

Step1: Analyze right trapezoid angles

A trapezoid has 1 pair of parallel sides. If one angle is right, the adjacent angle on the same parallel side is also right (consecutive interior angles). The other two angles: if the non-parallel sides are perpendicular to the second parallel side, we get 2 more right angles. Total right angles: 3, so additional right angles = 3 - 1 = 2.

Step2: Analyze parallelogram with right angle

In a parallelogram, opposite angles are equal, consecutive angles are supplementary. If one angle is $90^\circ$, all angles are $90^\circ$. A parallelogram with 4 right angles is a rectangle (a square is a special rectangle, but the general case is rectangle).

Answer:

1. a. 2
2. c. rectangle