Sent in the lesson and got 10.000.
]]>I'm really pleased you got the others right. Excellent! OK, let's have a look at the new ones:
Area of Circles and Sectors
~What is the area of the circle if the radius is: ~
1. 4 - i said C
A 23*pi
B 18*pi
C 16*pi
D 34*pi
E 41*pi
F 60*pi
Correct.
2. SQRT(3) - i said B
A 9*pi
B 3*pi
C 1*pi
D 5*pi
E 6*pi
F 7*pi
Correct!
3. 7 - i said E
A 67*pi
B 53*pi
C 75*pi
D 82*pi
E 49*pi
F 34*pi
Correct!
4. 6x - i said D
A 29 x^2 * pi
B 84 x^2 * pi
C 65 x^2 * pi
D 36 x^2 * pi
E 15 x^2 * pi
F 75 x^2 * pi
Correct!
5. 10 - i said A
A 100*pi
B 89*pi
C 54*pi
D 72*pi
E 37*pi
F 55*pi
Correct!
~What is the radius if the area of the circle is: ~
6. 9(PI) - i said F
A 7
B 2
C 5
D 6
E 4
F 3
Correct!
7. 4x^2(PI) - i said B
A 5x
B 2x
C 9x
D 3x
E 6x
F 1x
Correct!
8. 25(PI) - i said A
A 5
B 7
C 9
D 15
E 8
F 4
Correct!
9. 81(PI) - i said A
A 9
B 3
C 5
D 7
E 2
F 6
Correct!
10. 5(PI) - i said D
A sqrt 7
B sqrt 3
C sqrt 8
D sqrt 5
E sqrt 4
F sqrt 9
Correct!
11. (9/16)PI - i said E
A 7/6
B 3/1
C 5/2
D 9/5
E 3/4
F 4/1
Correct!
12. 25y^2(PI) - i said D
A 9y
B 3y
C 6y
D 5y
E 2y
F 10y
Correct!
13. 16z^2(PI) - i said C
A 9z
B6z
C4z
D7z
E 5z
F 2z
Correct!
14. t^2(PI) - i said D
A 3.146
B 5
C 2
D t
E 9
F 7
Correct!
15. (PI) - i said E
A 2
B 6
C 8
D 3
E 1
F 5
Correct!
~What is the area of the sector if the radius is 6 and the degree measure is: ~
16. 26 - i said C
A 1.9*pi = 9.523
B 6.7*pi = 3.491
C 2.6*pi = 8.168
D 5.1*pi = 7.054
E 9.2*pi = 3.115
F 7.8*pi = 1.274
Correct!
17. 30 - i said F
A 6*pi
B 5*pi
C 9*pi
D 1*pi
E 6*pi
F 3*pi
Correct!
18. 50 - i said A
A 5*pi
B 4*pi
C 3*pi
D 9*pi
E 2*pi
F 7*pi
Correct!
19. 90 - i said D
A 8*pi
B 3*pi
C 1*pi
D 9*pi
E 7*pi
F 2*pi
Correct!
20. 120 - i said F
A 23*pi
B 74*pi
C 89*pi
D 24*pi
E 59*pi
F 12*pi
Correct!
That's excellent. You have certainly done well with these.
Bob
]]>Area of Circles and Sectors
~What is the area of the circle if the radius is: ~
1. 4 - i said C
A 23*pi
B 18*pi
C 16*pi
D 34*pi
E 41*pi
F 60*pi
2. SQRT(3) - i said B
A 9*pi
B 3*pi
C 1*pi
D 5*pi
E 6*pi
F 7*pi
3. 7 - i said E
A 67*pi
B 53*pi
C 75*pi
D 82*pi
E 49*pi
F 34*pi
4. 6x - i said D
A 29 x^2 * pi
B 84 x^2 * pi
C 65 x^2 * pi
D 36 x^2 * pi
E 15 x^2 * pi
F 75 x^2 * pi
5. 10 - i said A
A 100*pi
B 89*pi
C 54*pi
D 72*pi
E 37*pi
F 55*pi
~What is the radius if the area of the circle is: ~
6. 9(PI) - i said F
A 7
B 2
C 5
D 6
E 4
F 3
7. 4x^2(PI) - i said B
A 5x
B 2x
C 9x
D 3x
E 6x
F 1x
8. 25(PI) - i said A
A 5
B 7
C 9
D 15
E 8
F 4
9. 81(PI) - i said A
A 9
B 3
C 5
D 7
E 2
F 6
10. 5(PI) - i said D
A sqrt 7
B sqrt 3
C sqrt 8
D sqrt 5
E sqrt 4
F sqrt 9
11. (9/16)PI - i said E
A 7/6
B 3/1
C 5/2
D 9/5
E 3/4
F 4/1
12. 25y^2(PI) - i said D
A 9y
B 3y
C 6y
D 5y
E 2y
F 10y
13. 16z^2(PI) - i said C
A 9z
B6z
C4z
D7z
E 5z
F 2z
14. t^2(PI) - i said D
A 3.146
B 5
C 2
D t
E 9
F 7
15. (PI) - i said E
A 2
B 6
C 8
D 3
E 1
F 5
~What is the area of the sector if the radius is 6 and the degree measure is: ~
16. 26 - i said C
A 1.9*pi = 9.523
B 6.7*pi = 3.491
C 2.6*pi = 8.168
D 5.1*pi = 7.054
E 9.2*pi = 3.115
F 7.8*pi = 1.274
17. 30 - i said F
A 6*pi
B 5*pi
C 9*pi
D 1*pi
E 6*pi
F 3*pi
18. 50 - i said A
A 5*pi
B 4*pi
C 3*pi
D 9*pi
E 2*pi
F 7*pi
19. 90 - i said D
A 8*pi
B 3*pi
C 1*pi
D 9*pi
E 7*pi
F 2*pi
20. 120 - i said F
A 23*pi
B 74*pi
C 89*pi
D 24*pi
E 59*pi
F 12*pi
1. c correct
2. f correct
3. a correct
4. d correct
5. f correct
I'm not getting these either at the moment. If L is an arc of a circle but what is n ?
Or can you post a diagram?
LATER EDIT:
Is n the angle at the centre?
So what fraction is that angle of a complete turn. eg 90 degrees is one quarter of 360.
That is the same as the fraction made by arc length divided by circumference.
ie.
This seems to work in the sense that each gives one of the multi-choice answers.
Bob
]]>What is the radius if:
1. n=30 L=1/3xy(pi)
A 6xy
B8xy
C2xy
D10xy
E 3xy
F 14xy
2. n=40 L=8/9(t)(pi)
A 20t
B5t
C9t
D18t
E 12t
F 4t
3. n=15 L=(21/36)pi
A 7
B21
C28
D62
E 56
F 14
4. n=5 L=1/2pi
A 24
B30
C45
D18
E 66
F 39
5. n=18 L=6(y)pi
A 30y
B45y
C120y
D90y
E 15y
F 60y