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: Relate addition and subtraction to length.

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

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

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

Tell and write time.

Work with time and money.

Represent and interpret data.

Describe and compare measurable attributes.

Measure and estimate lengths in standard units.

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

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

Convert like measurement units within a given measurement system.

Measure lengths indirectly and by iterating length units.

Geometric measurement: understand concepts of angle and measure angles.

Classify objects and count the number of objects in each category.
problem_activity: Narrative
In a previous lesson, students described an angle to a peer so that they might draw the angle accurately without seeing it. Students learned what an angle is and have reasoned about how to describe the size of an angle.
In this activity, students use the features of an analog clock (minute hand, hour hand, and position of numbers) to explain how to draw a given angle. In doing so, they use language related to turning one or both hands on the clock. In future activities, students will relate this idea to turning a ray around a fixed point.
The hands on an actual clock are designed so that moving the minute moves the hour hand. The examples here disregard this constraint. For the purposes of this activity, it is assumed that both hands can be moved freely, or that one hand can be held in place while the other moved freely.
Required Materials
Materials to Gather
Rulers or straightedges
Launch
Groups of 2
Give students access to rulers or straightedges.
Activity
“In an earlier lesson, we played a game where you described an angle to your partner to help them draw it without seeing it.”
“Read Andre’s explanation for how to draw an angle. Try to draw his angle, and then think of another way to describe how to draw the same angle.”
3 minutes: independent work time on the first two problems
“Share your drawing and description with your partner.”
“Discuss how you would explain how to draw the other angles.”
3–5 minutes: partner discussion and work time
Monitor for students who clearly describe turning a hand around the clock and who connect the hands to the rays of the angles.
Student Facing
Andre used the hands of a clock to explain how to draw an angle to his partner.
“Imagine both hands are pointing at the 12. Turn the minute hand so it's pointing at the 3.”
[IMG]
Draw Andre’s angle.
What is another way to describe how to draw the same angle using the clock?
Use Andre’s way to explain how to draw these angles:
[IMG]
[IMG]
[IMG]
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
“Let’s listen to some different directions for how to draw these angles. As you listen, try to sketch the angle and guess which one they are describing how to draw.”
Invite 2–3 students to share the directions they wrote for drawing one of the angles. Choose students to share in a different order than the angles are presented in the task.
For each, consider asking:
“Which angle did they describe (a, b, or c) and how do you know?”
“What words help you picture how to draw the angle?” (turn right, turn left, point at 4)
“We can describe the size of an angle by explaining how much one ray has turned from the other.”


correct_option_index: 13