few_shots: 
Example:
Concept/skill: 
Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.

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


Answer: 
Yes. An initial step when solving for x in this problem requires the use of the addition formula for cosine on the left side of the equation.

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_pos_0

HS_0
standard_description: Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles. For example, arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so.
problem_activity: Narrative
The purpose of this activity is for students to learn stage 1 of the Build Shapes center. Students use straws and clay to build a shape of their choice. Students check with their partner to be sure they both agree that the shapes match. The Build Shapes Cards are printed in the student book for this activity. The Build Shapes Cards blackline master is available for students to use during center activities in future lessons. Listen to how students create an argument and use or revise their language to make their argument clear to others (MP3, MP6).
After they participate in the center, students choose from any stage of previously introduced centers.
Counting Collections
Which One
Picture Books
Bingo
Shake and Spill
Required Materials
Materials to Gather
Materials from a previous activity
Materials from previous centers
Materials to Copy
Build Shapes Stage 1 and 2 Cards
Required Preparation
Students need the bags of straws and clay from the previous activity.
Gather materials from:
Counting Collections, Stage 1
Which One, Stage 1
Picture Books, Stages 1–3
Bingo, Stages 1 and 2
Shake and Spill, Stages 1 and 2
Launch
Groups of 2
Give each group clay and straws.
“We are going to learn a center called Build Shapes. You will choose a shape. Then you and your partner will both use the straws and clay to build that shape. When you are both finished, compare your shapes and make sure they both match the shape you chose.”
Activity
8 minutes: partner work time
Monitor for two students who build different rectangles to share in the lesson synthesis.
“Now you can choose another center. You can also continue playing Build Shapes.”
Display the center choices in the student book.
Invite students to work at the center of their choice.
8 minutes: center work time
If time, invite students to choose another center.
Student Facing
[IMG]
Choose a center.
Build Shapes
[IMG]
Counting Collections
[IMG]
Which One
[IMG]
Picture Books
[IMG]
Bingo
[IMG]
Shake and Spill
[IMG]
Activity Synthesis
Display a square built from 4 straws that are the same length.
Display a rectangle from the shape cards.
“Han was trying to build this shape. What should Han change so his shape will match the shape on the card?”


aligns: no