Name:______Date:______Period:_____
Chapter 3 – Constructions Review
Constructions to know: / Centers to know: / Algebra to know:- Medians
- Centroid
- 1-2-3 Rule
- Coordinates on a plane (average)
- Angle Bisectors
- Incenter (with circle!)
- All radii are equal in measure
- Perpendicular Bisectors
- Circumcenter (with circle!)
- All radii are equal in measure
- Altitudes
- Orthocenter
- Congruent Segment
- Congruent Angle
- Equilateral Triangle
- 300 Angle
- Parallel Lines
Directions: Answer the following questions completely. Justify your calculations for each question.
1. The intersection of the perpendicular bisectors is called the: ______
2. The intersection of the angle bisectors is called the: ______
3. The intersection of the altitudes of a triangle is called the: ______
4. The intersection of the medians of a triangle is called the: ______
5. What is the center of the circle that is inscribed inside a triangle? ______
6. What is the center of the circle that is circumscribed around a triangle? ______
7. In the diagram below of ΔABC, medians AD, BE, and CF intersect at G.
If CF = 24, what is the length of FG?
(1) 8(2) 10(3) 12(4) 16
8. In the diagram of ΔABC below, Jose found the centroid P by constructing the three medians. He measured CF and found it to be 6 inches.
If PF = x, which equation can be used to find x?
(1) x + x = 6(2) 3x + 2x = 6(3) 2x + x = 6(4) x + x = 6
9. In triangle ABC, medians, , and 10. P is the incenter of . If m<SZP = 7x + 7,
are concurrent at point P. If AP = 8, find the length and m<SZT = 16x + 4, find the value of xand
of median .m<SZT.
11. In triangle ABC, medians, , and 12. The circumcenter of ΔABC is point P. If AP=x+2y,
are concurrent at point P. If AP=7x+1 and DP = 4x-2,BP = 40, and CP = x + 4, find x and y.
then what is the value of x?
13. Given triangle ABC with coordinates A(3,10),14. In triangle ABC, medians AD and BE intersect
B(-6,2), and C(-9,3). What are the coordinates of the atP. If BE = and BP= , find the length
centroid of triangle ABC?of BE.
15. The perpendicular bisectors of triangle ABC 16. Given triangle ABC with coordinates A (3, -1),
intersect at point P. If AP=20, BP=2x+4, and B (9,5), and C (-3, 2), find the coordinates
CP=3y-7, what is the value of x and y?of the centroid oftriangle ABC.
17. In triangle ABC, medians, , and are 18. P is the incenter of . If m<SXP = 7x,
concurrent at point P. If FP=x+1 and FC = 6x-12, then and m<RXP = 2x+50, find the value of x
what is the value of x?and m<SXP.
Directions: Answer the following questions completely.
19. The diagram below illustrates the construction of parallel to through point P.
Which statement justifies this construction?
(1)
(2)
(3)
(4)
20. The diagram shows the construction of the bisector of .
Which statement is not true?
(1)
(2)
(3) (4)
21. The diagram below shows the construction of the perpendicular bisector of
Which statement is not true?
(1)
(2)
(3)
(4)
22. Which geometric principle is used to justify the construction below?
(1) A line perpendicular to one of two parallel lines is perpendicular to the other.
(2) Two lines are perpendicular if they intersect to form congruent adjacent angles.
(3) When two lines are intersected by a transversal and alternate interior angles are congruent, the lines are parallel.
(4) When two lines are intersected by a transversal and the corresponding angles are congruent, the lines are parallel.
23. Which diagram shows the construction of the perpendicular bisector of
24. Which diagram represents a correct construction of equilateral , given side
Directions: Answer the following questions completely using a compass and a straightedge. Remember to leave all construction marks.
25. Construct an angle congruent to . Label this new angle as .
26. Construct an angle bisector of .27. Construct an angle bisector of .
28. On theline segment below, construct equilateral 29. Triangle ABC is shown. Is this an equiateral
triangle ABC.Triangle? Justify your answer.
30. Using the equilateral triangle below, construct31. Construct a perpendicular bisector.
a 30 degree angle.
32. For the following, construct a line perpendicular through the given points.
33. Construct a line parallel through the given point.
34. There are two boys kicking a soccer ball at a field. They are both equidistant from each other. Their friend wants to join. Where would the third boy have to stand in order for them to all be equidistant from each other. Label this .
35. Mrs. Fields lives at home. She has a large, rectangular shaped backyard. Mrs. Fields runs both a dog-sitting business and a daycare service. She wants to install a fence that is equidistant from the doghouse and the playground, to keep her businesses separate. Use your construction tools to determine where the fence should go on the plot of land.
**If you want to practice more constructions, re-draw the diagrams above in any size you want and you can practice this way**