few_shots: 
Example:
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.

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
standard_description: Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.
problem_activity: Task
Consider a circle with center $O$ and let $P\,$ be a point on the circle. Suppose $L$ is a tangent line to the circle at $P$,  that is $L$  meets the circle only at $P$.
[IMG]
Show that $\overline{OP}\,$ is perpendicular to $L$.


aligns: no