standard_description: Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles.
problem_activity: Using the diagram below:
[IMG]
What can be concluded about the relationship between line
$$l$$
and plane
$$P$$
? Why?
What can be concluded about the relationship between planes
$$P$$
and
$$Q$$
? Why?
What can be concluded about the relationship between lines
$$l$$
and
$$m$$
? Why?
What can be concluded about
$$\overline{AB}$$
and
$$\overline{CD}$$
?
Line
$$j$$
lies in plane
$$P$$
, and line
$$i$$
lies in plane
$$Q$$
. What can be concluded about the relationship between lines
$$i$$
and
$$j$$
?


aligns: no