Finding the missing angle

This task provides us with the opportunity to see how the mathematical ideas embedded in the

standards and clusters mature over time. The task “Uses facts about supplementary,

complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple

equations for an unknown angle in a figure (7.G.5)” except that it requires students to know, in

addition, something about parallel lines, which students will not see until 8th grade. As a result,

this task is especially good at illustrating the links between related standards across grade

levels.