**Geometry Journal Entries**

11.1: Your 5^{th} grade students are
learning to use protractors to measure angles.
Several of your students measured the angle below as 130°. a) Why do you
believe the students are incorrectly reporting the measurement of 130°? b) How
could you enable your students to see why their measurement is incorrect? What exactly would you say to the student? (be specific)

11.2: a) Compare and contrast figure A with figure B
(below). (Note: Compare means to tell
how they are alike. Contrast means to
tell how they are different.) b) Explain why every square is a rectangle but
not every rectangle is a square.

13.1: Your student, Shelly, measured the segment
pictured below as 1.4 inches. a) What do you believe Shelly’s reasoning was
that led to this response? b) Explain to Shelly WHY her answer is incorrect and
how she should use the ruler to correctly find the measurement.

11.3: In class we saw that the sum of the interior
angles for a convex n-gon can be found using the
formula (n-2)180. Explain in your own
words why this formula works.

11.4: Compare and contrast a square-based prism with
a square-based pyramid. Include a
drawing of each.

12.1: Construct with a straightedge and compass an
angle that is congruent to the angle below.
Include a written description of the steps you take.

12.2: Explain in your own words why “ASS” is not
enough information for showing two triangles are congruent. Include example triangles to support your
reasoning. Triangles should be
accurately drawn.

12.3: Provide a written description of the steps
taken in constructing an angle bisector.
How is this process related to a rhombus and its properties?

12.4: Explain why 2 square are always similar but 2
rectangles are not always similar.

13.2: Many people incorrectly believe that since
there are 3 feet in one yard, there are also 3 square feet in a square
yard. Provide a conceptually-based
explanation of why this is not true. Be
sure to include drawings to support your explanation.

13.3: a) Explain how to find the length of the side
labeled x in the triangle below. b) Find the perimeter and area of the
triangle. c) If you triple the length of each side of the triangle, what do you
believe will happen to the perimeter? To the area? d) Test your conjecture from part c. Were you correct? Why do you believe you obtained these
results?

13.4: What is meant by the phrase “surface
area”? Explain how to find the surface
area of a rectangular prism. Include an
example.

13.5: Fran reported that the volume of her cone was
50 inches. Explain to Fran why it is
incorrect to report volume in inches.
Include with your explanation a description of what a cubic inch looks
like and what it means to have a volume of 50 cubic inches.

14.1: Examine the pre-image and the image of the
equilateral triangle. Explain how you
know that the image is not the result of a translation. Explain how you know it is the result of a
rotation.

14.2: Examine the pre-image and the image from the
previous entry. Explain how you know
that the image in not the result of a reflection.

14.4: Compare and contrast rotational symmetry and
point symmetry.

14.5: Provide a thorough explanation of why a
regular pentagon will not tile a plan.

14.3: Will the image of perpendicular line under a
size transformation always be perpendicular lines?