few_shots: 
Example 1:
Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


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.

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


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).

Answer: 
No. This task does not involve an equation in two variables. There is only one variable, x.

Example 3:
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 $P$.


Concept/skill: 
Construct a tangent line from a point outside a given circle to the circle.

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: Prove theorems about lines and angles. Theorems include: vertical angles are congruent; when a transversal crosses parallel lines, alternate interior angles are congruent and corresponding angles are congruent; points on a perpendicular bisector of a line segment are exactly those equidistant from the segment’s endpoints.
problem_activity: Problem 1
Based on the definition of each feature of a circle below, label the circle with the appropriate vocabulary words.
Arc:
Part of any curve
Central angle:
An angle formed by two radii with the vertex as the center of the circle
Chord:
A line segment containing two points on a curve
Diameter:
A line segment connecting two points on a curve that passes through the center of the circle
Radius:
A line segment that connects the center of a circle and a point on the circle
Tangent:
A line that intersect a circle at one and only one point
[IMG]
Problem 2
Below is circle
$$A$$
with points
$$E$$
,
$$C$$
,
$$D$$
, and
$$B$$
on the circle.
$$\angle EAC \cong \angle DAB$$
.
[IMG]
What is the relationship between
$$\overline{BD}$$
and
$$\overline {EC}$$
?
Problem 3
Given diameter
$$\overline{CB}$$
, chords
$$\overline{DB}$$
and
$$\overline{CD}$$
, and radii
$$\overline{AC}$$
,
$$\overline{AD}$$
, and
$$\overline{AB}$$
, find the measure of
$$\angle CDB$$
.
[IMG]


aligns: no