Scale Factor and Ratio of Areas in Similar Triangles

District Formative Assessment

Scale Factor and Ratio of Areas in Similar Triangles

Investigation #2

Student Response(s)
Right On / Developing / Developing / Not yet
Possible Indicators / Possible Indicators / Possible Indicators / Possible Indicators
a) Finds hypotenuse
b)Proportions of all sides correct & shown
c)Correct similarity statement (6 possible)
d) Correct scale factor
e)Justifies perimeter answer
f)Correct perimeters
g) Correct perimeter ratio
h)Justifies area answers
i)Correct area ratio / a) Hypotenuse not shown
b)Proportions of all not shown
c)Similarity statement not shown
d) Correct scale factor
e)No justification of perimeter answer
f)Correct perimeters
g) Correct perimeter ratio
h)No justification of area answers
i)Correct area ratio / a) Incorrect hypotenuse
b)Proportions of all sides shown but incorrect
c)Incorrect similarity statement
d)Incorrect scale factor
e)Justifies perimeter answer
f)Incorrect perimeters
g) Correct perimeter ratio
h)Justifies area answers
i)Correct area ratio / a) Finds one correct hypotenuse
b)Proportions of all sides not shown
c)Incorrect similarity statement
d)Incorrect scale factor (none shown)
e)Incorrect perimeter justification
f)Incorrect perimeter
g) Incorrect perimeter ratio
h)Incorrect area justification
i)Incorrect area ratio
Next Steps
Developing / Developing / Not Yet
How do you know if two the triangles are similar?
How did you find the scale factor? / How do you know if two triangles are similar?
How did you find the scale factor? / How do you know if two triangles are similar?
How did you calculate the hypotenuse of each triangle? / How did you calculate the hypotenuse of each triangle? / How did you calculate the hypotenuse of eachtriangle?
How did you find the ratio of the perimeters?
How did you find the ratio of the areas? / How do you reduce a fraction?

In the Moment Questions/Prompts