Circles
The line that cuts a circle in half passing through the center is called...
The diameter
In the equations Y=Kx
What does K represent?
The constant of proportionality
or
The Scale Factor
- 8 + 7 =
- 8 x 7 =
-1
-56
T or F. Scaled copy is a copy of a figure where every length in the original figure has the same number added to it?
False. A scaled copy is a copy of a figure where every length in the original figure is multiplied by the same number.
What is 7.5% tax on $73
Round of to the nearest hundredth
.075 x 73 = 5.48
The line connecting the center of a circle to the outer edge is called...
What is the constant of proportionality
5:35
3:21
1:7
K = 7
13 - - 8 =
-28 - 7 =
21
-35
What is the scale factor for these triangles
5:3:4
30:18:24
The scale factor: 3
6,952 x 6 =
41,712
Name both of the formulas used to find the circumference of a circle and the area formula
C = Diameter x Pi
C = 2 x Pi x Radius
A = Pi x Radius sq
Fill in the missing factor. What is the constant of proportionality?
2:30
9:
5:75
135
K = 15
282 x (- 19) =
243 / (- 3) =
-5,358
-81
T or F. These squares are scaled copies of each other. Use evidence to support your claim.
5:9:5:6
15:28:15:18
These squares would NOT be scaled copies of each other. The 2nd the lengths should be 9:27 because the scale factor is 3 9 x 3 = 27
What do you call an angle that is 76.5 degrees
An acute angle
What equations would be used to find the circumference of a circle with a radius of 18
c = 2 x pi x 18
c = 36pi
Fill in the missing factor. What is the constant of proportionality?
17:25.5
__:13.5
32:48
9
SF = 1.5
Rewrite both equations are DIFFERENT AND EQUIVALENT equations
434 + (-98) =
(-573) -57 =
434 - 98 =
(-573) + (-57) =
Name the scale factor:
60:36:84
5:3:7
Scale Factor: 12
pi is an example of what kind of number?
an irrational number
Find the circumference and area of a circle with a radius of 23. Round to the nearest tenth.
C = 144.5 units
A = 1,661.9 units sq
Explain how pi and constant of proportionality relate
Pi is the constant of proportionality of all diameters when you are finding the circumference of a circle because you HAVE to multiply every circle's diameter by pi to find circumference.
Rewrite both equations are DIFFERENT AND EQUIVALENT equations. Then Solve.
56 - (-32) =
76 x (-48) =
56 + 32 = 88
(-48) x 76 = - 3,648
Fill in the missing side lengths of the parallelogram. Name the scale factor.
24: __ : 72: 120
3: ___ : 9: ___
___, ____ (the 1st factor is a factor of 8; the 2nd is divisible by 8)
15
Scale Factor: 8
T or F. 27 is 15% of 180
Prove it.
True. 27 / 0.15 = 180