Geo_Book_Answers

LESSON 1.7
1. Answers will vary. Sample answers:The green
areaintheirrigationphotoisacircle,thewaterisa
radius,and a path on the far side of the circle appears
to be tangent to the circle.The wood bridge is an arc of
a circle,and the railings are arcs of concentric circles.
The horizontal support beam under the bridge is
achord.
2. three of the following: AB, BD, EC, EF
3. EC
4. AP, EP, FP,BP, CP
5. five of the following: EF ,AE ,AB ,BC ,CD ,DF ,
EB ,ED ,FC ,AC ,DB ,AF ,AD ,BF
6. EDC
or EFC
,EBC
or EAC
7. two of the following: ECD
,EDF
,FEC
,DEC
,...
8. FG , HB
9. either F or B
10. possible answers: cars, trains, motorcycles;
washing machines, dishwashers, vacuum cleaners;
compact disc players, record players, car racing,
Ferris wheel
11. mPQ 110°; mPRQ
250°
12.
13. possible answers: concentric rings on cross
sections of trees (annual rings),bull’s-eye or target,
ripples from a rock falling into a pond.
14.
15.
65
215
P Q
16. Equilateral quadrilateral. (The figure is
actually a rhombus, but students have not yet
learned the properties needed to conclude that the
sides are parallel.)
17. equilateral; 3 to 1
18.
19. yes; yes
20. yes; no
21. no; no
8
–5
–5
y
P
s
5
–5
5
–5
B
y
y
A
Q
5
5
x
x
8 16
x
ANSWERS TO EXERCISES 17
Answers to Exercises