Triangle abc has been rotated 90° to create triangle def. using the image below, prove that lines bc and ef have the opposite and reciprocal slopes. you must show all of your work to receive credit.

The construction of copying qpr is started below. the next step is to set the width of the compass to the length of ab. how does this step ensure that a new angle will be congruent to the original angle? by using compass take the measures of angle and draw the same arc according to it.