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, assess whether the following problem or activity is 'aligned' with the given Common Core standard in Mathematics.

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: Fluently add and subtract within 20 using mental strategies. (See standard 1.OA.6 for a list of mental strategies.) By end of Grade 2, know from memory all sums of two one-digit numbers.
problem_activity: Narrative
The purpose of this activity is for students to use what they know about making a ten to identify which addition expressions are equivalent to
\(10 + n\)
expressions. Students should have access to double 10-frames and connecting cubes or two-color counters.
The Compare Stage 2 Addition Cards will be used again in a later lesson.
Required Materials
Materials to Gather
Connecting cubes or two-color counters
Double 10-frames
Materials to Copy
Compare Stage 2 Addition Cards to 20
Required Preparation
Create a set of Compare Stage 2 Addition Cards to 20 from the blackline master for each group of 3.
Launch
Groups of 3
Give each group a set of cards and access to double 10-frames and connecting cubes or two-color counters.
Activity
Read the task statement.
8 minutes: small-group work
Student Facing
Take out all the expression cards that have the number 10.
Mix up the rest of the cards.
Pick a card.
Place the card under the expression with 10 that it is equal to.
[IMG]
Student Response
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Activity Synthesis
“We are going to create a poster and do a Gallery Walk.”


aligns: no