few_shots: 
Example 1:
Concept/skill: 
Understand that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.

Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


Answer: 
No. This problem does not directly teach how side ratios in right triangles lead to definitions of trigonometric ratios. Instead, it involves solving a trigonometric function.

Example 2:
Concept/skill: 
Understand that the graph of an equation in two variables is the set of all its solutions plotted in the coordinate plane, often forming a curve (which could be a line).

Problem/activity:
Task
Solve the quadratic equation
$$ x^2 = (2x - 9)^2 $$
using as many different methods as possible.


Answer: 
No. This task does not involve an equation in two variables. There is only one variable, x.

Example 3:
Concept/skill: 
Construct a tangent line from a point outside a given circle to the circle.

Problem/activity:
Task
Suppose $A$ is an angle with vertex $P$, as pictured below:
[IMG]
Draw a circle with center $P$ and with  radius $r \gt 0$.  Explain why the circle
meets each ray of angle $A$ in a single point.  Label these points $Q$ and $R$ respectively.
Draw circles with centers $Q$ and $R$ respectively and radius $r$.  These circles meet at $P$ and a second point to be labelled $B$.
Show that ray $\overrightarrow{PB}$  bisects angle $P$.


Answer: 
No. This task does not involve drawing lines that are tangent to circles. The only line that may be drawn is the ray between points P and B.

Now, determine whether the following problem or activity can enable students to understand the concepts or skills in the provided description.

shot_info: fl_problem_001894_neg_0

HS_0

im_task_000870_neg_0

HS_1

im_task_001160_neg_0

HS_2
standard_description: Distinguish between defining attributes (e.g., triangles are closed and three-sided) versus non-defining attributes (e.g., color, orientation, overall size); build and draw shapes to possess defining attributes.
problem_activity: Task
As a whole group, students will sort a collection of three-dimensional objects into categories by shape. There should be several that fall into each of the categories below:
sphere
cone
pyramid
cube
cylinder
rectangular prism
As a class, students brainstorm attributes of the objects they have classified, and the teacher writes those attributes where the entire class can see them. Students then use one of the following sentence frames as they classify the objects. The sentence frames should be written on sentence strips or some other large paper so that the entire class can read/see them during the activity.)
The ___________ is in the shape of a __________ . It is/has __________ , just like all ____________.
The ___________ is in the shape of a __________ . It is/has ___________ , but some ___________ aren't/don't.
The teacher models with one or two objects to start. An example would be:
"The can is in the shape of a cylinder. It has circles on the ends, just like all cylinders."
"The can is a in the shape of a cylinder. It is made of metal, but some cylinders aren't."
This will help students distinguish between defining attributes and non-defining attributes.
Once students are familiar with this task they can be given a set of cards and can work in pairs to classify by defining attribute using the (now familiar) sentence frames.


aligns: yes