Readiness Check

Early in the unit, students are introduced to the vocabulary words “complementary” and “supplementary” as they pertain to angles. Later, students will write equations to solve for the measure of an unknown angle, where one of the givens is that two angles together form a right angle. 

If most students struggle with this item, reinforce the fact that we call an angle with a measurement of 90 degrees a right angle.

Throughout the unit, students are expected to measure angles with a protractor in order to make conjectures such as “vertical angles are equal.”

If most students struggle with this item, incorporate practice with a protractor before Lesson 2 Activity 2. An optional activity in Lesson 1 might also be a good place to revisit how a protractor is used to measure angles.

In this unit, students investigate the number of distinct polygons or triangles that can be drawn with given information: for example, two sides and an angle. In some cases, students use protractors as a tool in constructing these shapes.

If most students struggle with this item, plan to incorporate drawing angles on tracing paper into earlier activities to verify the measures of angles that are given. Students can place their tracing paper over the printed angles to check their drawings.

The vocabulary words in the Student Task Statement are all background for the geometric work of this unit. Watch for students drawing an obtuse angle instead of an obtuse triangle. 

If most students struggle with the term "parallel," discuss in Lesson 9 Activity 3 that one of the triangles is impossible to draw because two sides end up being parallel. In Lesson 11, students may not have experience with parallel planes. Connect the idea of parallel lines with parallel planes.

If most students struggle with the term "perpendicular," define “perpendicular” in Lesson 2 Activity 2 where students are told that they do not need to make a cut "perpendicular to the side of the paper." Perpendicular lines come up again in Lesson 3 Activity 3, as students learn that intersecting lines need not be perpendicular.

If most students struggle with the terms “acute” and “obtuse,” define those terms in Lesson 1 Activity 1. Consider making an anchor chart with names and types of angles that will be used throughout this unit.

In this unit, students study volume and surface area. In grade 6, they learned to calculate the volume of a rectangular prism. They also learned to calculate the surface area of prisms and other solids by adding up the area of each face.

If most students struggle with this item, revisit it with students prior to Lesson 12, helping them to recall what they know about finding the volume of right rectangular prisms. You may also choose to present right rectangular prisms with given side lengths to find the volume, in addition to this item which has a volume given.

If most students do well with this item, Optional Activity 4 in Lesson 12 gives students an opportunity to explore the same idea but with prisms other than right rectangular prisms.

The volume formula for the area of a rectangular prism will be familiar to students because it was covered in grade 6. They will not have had as much experience solving for height given volume. However, this problem provides students with an opportunity to connect their sixth-grade work with their more recent work solving equations. Watch for students making the error of ignoring the change in units (width of 3 feet versus 3 inches). 

If most students struggle with this item, discuss in Part 2 of Activity 1 what we can tell about unknown side lengths of a right rectangular prism if we know something about the volume. You may connect this to the equation-solving work students did in a prior unit. If students struggle to convert between feet and inches, that is not an expectation of this unit and does not need to be addressed for success.

In grade 6 students used strategies such as decomposing, rearranging, enclosing, and subtracting to calculate the area of polygons. In this unit, students will apply these strategies to find the area of the base of a prism, when studying volume and surface area.

If most students struggle with this item, review these strategies and spend extra time discussing Lesson 13 Activity 2. Revisit this item and, during the Activity Synthesis of Lesson 13 Activity 2, invite students to share how they could use these strategies to find the area of the trapezoid.