1. Tri-Math-Alon: Ch. 5+ Round 1: Formulas and Definitions
Round 2: Triangles
Round 3: Polygons and Parallelograms

2. Rules Divide yourself up into teams of 3 or 4. Do NOT move desks!
Round 1 is the speed round. The first team to write the FULL, CORRECT answer LEGIBLY will earn 1 point. The writer must switch after each question.
Rounds 2 & 3 you will work as a group to answer the question in a given amount of time. When time is called, hold up your answer board. ALL teams with the correct answer will get 2 points. Answers must be rounded correctly and use the correct units where applicable.
All participants get a 10/10 participation grade. Winners get extra credit on today’s grade! st place = 5 pts, 2nd place = 3 pts.

3. Round 1 Question 1: Formulas & Definitions
Fill in the blank: The point of concurrency of perpendicular bisectors is a _________.
Circumcenter

4. Round 1 Question 2: Formulas & Definitions
Fill in the blank: The point of concurrency of medians is a _________.
centroid

5. Round 1 Question 3: Formulas & Definitions
Fill in the blank: A segment that connects a vertex of a triangle to the midpoint on the opposite side is a(n) ___________.
median

6. Round 1 Question 4: Formulas & Definitions
Fill in the blank: A segment that connects two midpoints of a triangle is a ____________.
midsegment

7. Round 1 Question 5: Formulas & Definitions
Fill in the blank: The point of concurrency of angle bisectors is a(n) ___________.
incenter

8. Round 1 Question 6: Formulas & Definitions
Fill in the blank: A segment that cuts an angle in half is a(n) ______________.
Angle bisector

9. Round 1 Question 7: Formulas & Definitions
Fill in the blank: A segment that cuts a segment in half at a right angle is a(n) _________________.
Perpendicular bisector

10. Round 1 Question 8: Formulas & Definitions
What is the formula for the sum of the interior angles of a polygon?
(n-2)180

11. Round 1 Question 9: Formulas & Definitions
How do you find the length of a side of a triangle if you know the length of the corresponding midsegment?
Multiply the midsegment by 2

12. Round 1 Question 10: Formulas & Definitions
How do you find the length of the side of a right triangle if you know 2 side lengths and no other angles?
a2 + b2 = c2
or Pythagorean Theorem

13. Round 1 Is Done!

14. Round 2 Question 1: Triangles
In LUV, LU = 16cm, UV = 10cm, and LV = 25cm. List the angles of LUV from largest to smallest.
U, V, L

15. Round 2 Question 2: Triangles
In ABC, mA = (9x - 17), mB = (8x + 15), and mC = (3x + 22). List the side lengths of ∆ABC in order from shortest to longest.
AB, BC, AC

16. Round 2 Question 3: Triangles
A triangle has side lengths of 17ft and 29ft. What is the range of values for the length of the 3rd side?
12ft < x < 46ft

17. Round 2 Question 4: Triangles
Calculate the range of values for x.
- 3 < x < 9
50cm
(8x + 24)
75cm
96

18. Round 2 Question 5: Triangles
Solve for x. Round to the nearest tenth if necessary.
x = 16.6 yds

19. Round 2 Question 6: Triangles
Solve for x.
x = 6

20. Round 2 Question 7: Triangles
Solve for x AND y. Leave answers in simplest radical form.
x = units, y = 22 units

21. Round 2 Question 8: Triangles
Solve for x. Leave answers in simplest radical form.
x = units

22. Round 2 Is Through!

23. Round 3 Question 1: Polygons and Parallelograms
What is the sum of the interior angles of a heptagon?
900o

24. Round 3 Question 2: Polygons and Parallelograms
What is the measure of each interior angle of a regular hexagon?
120o

25. Round 3 Question 3: Polygons and Parallelograms
What is the measure of each exterior angle of a regular pentagon?
72o

26. Round 3 Question 4: Polygons and Parallelograms
FROG is a parallelogram. Solve for x. F R G O
(8x – 12 )
72
(5x – 3)
x = 15

27. Round 3 Question 5: Polygons and Parallelograms
QUAD is a parallelogram. Solve for x.
12x
10x + 30 Q U D A
15x
x = 6

28. And the winner is…?