Itried two ways to figure out 206-48 but both answers were different

The deck that kenneth is building is in the shape of a parallelogram abcd the measure of angle c is one third the measure of angle b find the measure of each angle of the deck

Polygons efgh and e′f′g′h′ are shown on the coordinate grid: what set of transformations is performed on efgh to form e′f′g′h′? a. a translation 1 unit to the left followed by a 90-degree counterclockwise rotation about the origin b. a translation 1 unit to the right followed by a 90-degree counterclockwise rotation about the origin c. a 90-degree clockwise rotation about the origin followed by a translation 2 units to the right d. a 90-degree clockwise rotation about the origin followed by a translation 2 units to the left

What are “like terms”? why can we only add like terms?