Download Drinking Straw Activity

Drinking Straw Activity
1. Cut drinking straws (dry spaghetti, etc.) to make representations of segments. Cut each
of the following lengths: 2 - 10cm, 1- 8cm, 3 - 6cm, 1 - 4cm, and 1 - 2cm.
2. Use the straw segments to assemble figures with the given lengths. (See Drinking Straw
Worksheet)
Complete the Drinking Straw Worksheet and use the Word List in order to answer the
following questions.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
What geometric shape(s) did you form?
Which figures could not be formed?
Which figures had no two sides congruent?
Which figures had two sides congruent?
Which figures had three sides congruent?
Which figures had no congruent angles?
Which figures had two congruent angles?
Which figures had three congruent angles?
What do you notice about the triangles that had:
a) No two sides congruent?
b) No two angles congruent?
c) Two congruent sides?
d) Two angles congruent?
e) Three congruent sides?
f) Three congruent angles?
Make a conjecture about the number of congruent sides of a triangle compared to the
number of congruent angles of the same triangle.



Compare the length of AC with the sum of the lengths of AB and BC for the figures that
can be formed. What do you notice?



Compare the length of AC with the sum of the lengths of AB and BC for the figures that
cannot be formed. What do you notice?
Make a conjecture about the sum of the lengths of two sides of a triangle and the length
of the third side.
Add the measure of angle A + the measure of angle B + the measure of angle C in each
of the figures. What do you notice?
Make a conjecture about the sum of the three angles of a triangle.
What is a three-sided figure called?
What is a triangle with no two sides congruent called?
What is a triangle with at least two congruent sides called?
What is a triangle with three congruent sides called?
What is a triangle with three acute angles called?
What is a triangle with one right angle called?
What is a triangle with one obtuse angle called?
What is a triangle with three congruent angles called?
Is an equiangular triangle also isosceles? Why or why not?
Is an isosceles triangle also equiangular? Why or why not?
Is it possible for a triangle to have more than one obtuse angle? Why or why not?
Is it possible for a triangle to have more than one obtuse angle? Why or why not?
Is it possible for a triangle to have only one acute angle? Why or why not?
Geometry in the Trees
Based on activities from Key Press Curriculum
Drinking Straw Activity
Suggested Answers
1. Cut drinking straws (dry spaghetti, etc.) to make representations of segments. Cut each
of the following lengths: 2 - 10cm, 1- 8cm, 3 - 6cm, 1 - 4cm, and 1 - 2cm.
2. Use the straw segments to assemble figures with the given lengths. (See Drinking Straw
Worksheet)
Complete the Drinking Straw Worksheet and use the Word List in order to answer the
following questions.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
What geometric shape(s) did you form? Triangles
Which figures could not be formed? Figure 4 and Figure 5
Which figures had no two sides congruent? Figures 2, 4, 5 and 7
Which figures had two sides congruent? Figures 1 and 3
Which figures had three sides congruent? Figure 6
Which figures had no congruent angles? Figures 2, 4, 5 and 7
Which figures had two congruent angles? Figures 1 and 3
Which figures had three congruent angles? Figure 6
What do you notice about the triangles that had:
a) No two sides congruent? They also had no two angles congruent.
b) No two angles congruent? They also had no two sides congruent.
c) Two congruent sides? They also had two congruent angles.
d) Two angles congruent? They also had two congruent sides.
e) Three congruent sides? They also had three congruent angles.
f) Three congruent angles? They also had three congruent sides.
Make a conjecture about the number of congruent sides of a triangle compared to the
number of congruent angles of the same triangle. The number of congruent sides in a
triangle is the same as the number of congruent angles of the same triangle.

Compare the length of AC with the sum of the lengths of AB and BC of the figures that
can be formed. What do you notice? The sum of AB and BC is greater than AC.

Compare the length of AC with the sum of the lengths of AB and BC of the figures that
cannot be formed. What do you notice? The sum of AB and BC is less than or equal to
AC.
Make a conjecture about the sum of the lengths of two sides of a triangle and the length
of the third side. The sum of the lengths of two sides of a triangle is greater than the
length of the third side.
Add the measure of angle A + the measure of angle B + the measure of angle C in each
of the figures. What do you notice? The three angles are equal to 180.
Make a conjecture about the sum of the three angles of a triangle. The sum of the three
angles of a triangle is equal to 180.
What is a three-sided figure called? A triangle.
What is a triangle with no two sides congruent called? Scalene Triangle
What is a triangle with at least two congruent sides called? Isosceles Triangle
What is a triangle with three congruent sides called? Equilateral Triangle
What is a triangle with three acute angles called? Acute Triangle
What is a triangle with one right angle called? Right Triangle
What is a triangle with one obtuse angle called? Obtuse Triangle
What is a triangle with three congruent angles called? Equiangular Triangle
Is an equiangular triangle also isosceles? Why or why not? Yes, because an isosceles
triangle has at least two congruent sides.
Is an isosceles triangle also equiangular? Why or why not? No, because an equiangular
triangle has three congruent sides.
Based on activities from Key Press Curriculum
28. Is it possible for a triangle to have more than one right angle? Why or why not? No,
because the three angles of a triangle must add up to 180. If two angles were right then
the third angle would have a measure of zero which is impossible.
29. Is it possible for a triangle to have more than one obtuse angle? Why or why not? No,
because the three angles of a triangle must add up to equal 180. If a triangle had two
obtuse angles then the two angles would have a sum greater than 180, which is
impossible.
30. Is it possible for a triangle to have only one acute angle? Why or why not? No, because
the three angle of a triangle must have a sum of 180. If a triangle only had one acute
angle, then the other two would have to be right, obtuse or both, giving the triangle an
angle sum greater than 180.
Based on activities from Key Press Curriculum