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: 
Solve quadratic equations in one variable.

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


Answer: 
Yes. This task shows one quadratic equation with 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, 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_neg_0

HS_0

im_task_000870_pos_0

HS_1

im_task_001160_neg_0

HS_2
standard_description: Use coordinates to prove simple geometric theorems algebraically. For example, prove or disprove that a figure defined by four given points in the coordinate plane is a rectangle; prove or disprove that the point (1, Ö3) lies on the circle centered at the origin and containing the point (0, 2).
problem_activity: Problem 1
Act 1: Watch the video
The Orange (Act-1)
.
a.   What do you notice? What do you wonder?
b.   How many linking cubes will it take to even out the balance scale? Make an estimate.
Problem 2
Act 2: Use the following information to determine how many cubes it will take until the balance is level with the orange -
[IMG]
[IMG]
Problem 3
Act 3: Watch
The Orange (Act-3)
. Was your answer reasonable? Why or why not?
Problem 4
Act 4 (the sequel):
a.   Jessica puts 28 grams of pinto beans and 36 grams of rice into a pot to make rice and beans. What is the total mass of the rice and beans?
b.   Lindsey bought 845 grams of potatoes at the grocery store. She uses some of them to make mashed potatoes. She now has 392 grams of potatoes left. How many grams of potatoes did Lindsey use to make the mashed potatoes?
c.   Jerry buys 6 bags of groceries. Each bag has a mass of 4 kilograms. What is the total mass, in kilograms, of Jerry’s grocery bags?


aligns: no