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: 
Solve quadratic equations in one variable.

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


Answer: 
Yes. This task shows one quadratic equation with 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_pos_0

HS_1

im_task_001160_neg_0

HS_2
standard_description: Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.
problem_activity: Narrative
The purpose of this activity is for students to create a connecting cube tower that is the same length as a given image. In the activity synthesis, students transition from describing the length of an object by comparing it to another object ("The earthworm is the same length as a tower of 8 cubes.") to describing the length of an object as a measurement ("The earthworm is 8 cubes long.").
Required Materials
Materials to Gather
Connecting cubes
Materials to Copy
Lengths of Creepy, Crawly Things
Launch
Groups of 2
Give each student connecting cubes and a copy of the blackline master.
Activity
“We just saw a picture that showed a pencil that was the same length as the purple tower. Use connecting cubes to build a tower that is the same length as each creepy, crawly thing.”
10 minutes: partner work time
Monitor for students who carefully line up the cubes with the endpoints of the images.
Student Response
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Activity Synthesis
Invite previously identified students to share.
Display the image of the caterpillar.
“How did you measure the caterpillar?” (I lined the first cube up with the end of the caterpillar. Then I added cubes until I got all the way to the other end of the caterpillar.)
“Since the tower of 4 cubes is the same length as the caterpillar and each cube has the same length, we can say the caterpillar is 4 cubes long.”
For each animal, invite students to say, “The ______ is ___ cubes long.”


aligns: no