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


Mathematical concept/skill options: 
A. Prove and apply trigonometric identities.
B. Model periodic phenomena with trigonometric functions.
C. Interpret functions that arise in applications in terms of the context.
D. Build a function that models a relationship between two quantities.
E. Define, evaluate, and compare functions.
F. Use functions to model relationships between quantities.
G. Understand the concept of a function and use function notation.
H. Analyze functions using different representations.
I. Extend the domain of trigonometric functions using the unit circle.
J. Interpret expressions for functions in terms of the situation they model.
K. Build new functions from existing functions.
L. Construct and compare linear and exponential models and solve problems.


Your response, in json format:
{
  "explanation": "This problem applies trigonometric identities, including the angle addition formula for cosine.",
  "answer": "A"
}

Now, assign the following problem or activity to one or more relevant mathematical concepts/skills it teaches.
shot_info: fl_problem_001894

HS
options: Geometric measurement: understand concepts of area and relate area to multiplication and to addition.

Represent and interpret data.

Measure lengths indirectly and by iterating length units.

Geometric measurement: recognize perimeter as an attribute of plane figures and distinguish between linear and area measures.

Geometric measurement: understand concepts of angle and measure angles.

Solve problems involving measurement and estimation of intervals of time, liquid volumes, and masses of objects.

Geometric measurement: understand concepts of volume and relate volume to multiplication and to addition.

Convert like measurement units within a given measurement system.

Solve problems involving measurement and conversion of measurements from a larger unit to a smaller unit.

Describe and compare measurable attributes.

Tell and write time.

Relate addition and subtraction to length.

Measure and estimate lengths in standard units.

Work with time and money.

Classify objects and count the number of objects in each category.
problem_activity: Narrative
The purpose of this activity is for students to order three objects by length. Students line up objects from shortest to longest and longest to shortest. Students need to attend to the language in the question to know which way to order the objects. The language and reasoning students use in this activity helps prepare them to compare the length of objects indirectly in future lessons.
Required Materials
Materials to Gather
Materials from a previous activity
Required Preparation
Each group of 4 needs the collection of objects from the previous activity.
Launch
Groups of 4
Give each group 10–12 objects.
Activity
Read the task statement.
5 minutes: small-group work
Monitor for students who line up the endpoints of the objects.
Student Facing
Pick 3 objects.
With your partner, put the objects in order from
shortest
to longest.
Trace or draw your objects.
Pick 3 new objects.
With your partner, put them in order from
longest to shortest
.
Write the names of the objects in order from longest to shortest.
Student Response
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Advancing Student Thinking
If students appear to order their objects correctly without lining them up, consider asking:
“How did you order your objects from ___ (shortest to longest or longest to shortest)?”
“How could you prove to someone that your objects are ordered correctly?”
Activity Synthesis
Invite previously identified students to demonstrate how they ordered three objects from shortest to longest.
Display the three objects with the endpoints lined up so all students can see.
“What statements can you make to compare the length of their objects?” (The ___ is longer than the ___ and ___.)
As time permits, repeat by inviting a previously identified students to demonstrate how they ordered three objects from longest to shortest.


correct_option_index: 2