7th GRADE MATH QUESTION! HELP?

Question

I love my teacher but he is killing me! help

show ur work or explain
doesn't matter who is first but which is better.

Using the given measurements, find the greatest and least possible circumferences and areas for each circle. use (pie)= 3.14. Round answers to the nearest hundredths.
1. 4 cm radius
2. 5.5 cm radius
3. 2.6 radius

i tryed to use my brain but i don't get how to find the greatest and least possable area and circum.

Answer 1

First of all,let me say that there is no greatest or least possible circumfrnce or area of a circle when the radius is fixed.The circle having greater radius will have greater circumference and greater area
1.Circumference=2XPiXr=2X3.14X4
=25.12 cm
Area=PiXrXr=3.14X4X4=50.24 cm^2
2.Circumference=2X3.14X5.5=34.54 cm
Area=3.14X5.5X5.5=94.99 cm^2
3,Circumference=2X3.14X2.6=16.33 cm
area= 3.14X2.6X2.6= 21.23 cm^2

Answer 2

let's see - circumference is pi times diameter
diameter = 2 radii

circles will have only one circumference - do not understand greatest and least part -
or
greatest will be #2 5.5 cm - since it is the biggest radius
least will be #3 - at 2.6 cm

so multiply each given times 2 times 3.14

#1....... 4 x 2 = 8 8 x 3.14 = 26.12

and that is the nearest hundredth

u do the other two !
u can do it!!!!

Answer 3

For the area of the 4 cm radius circle, the area is 50.24 cm squared, 5.5 cm radius has an area of 94.99 cm squared, and 2.6 cm radius has an area of 21.23 cm squared. I solved these using the formula for finding the area of a circle, A (area) = r (radius) squared times pi (3.14) (A = r x r x pi).

Next are the circumferences. The formula for finding this is c (circumference) = d (diameter) times pi (3.14). So for the circle with radius 4 cm, the circumference is diameter (8 cm) times pi which equals 25.12 cm, the circle with radius 5.5 cm has diameter 11, which when multiplied by pi = 34.54 cm. The last circle with radius 2.6 cm has diameter 5.2 cm. 5.2 x 3.14 = 16.33 cm. Don't forget to include the units! I hope I helped!

Answer 4

it truly is no longer obvious to guage 3/8 and a couple of/3, yet seem at it this way: might want to you really slice a pie into 3 products and take 2 (2/3 of a pie), or slice it into 8 products and take 3 (3/8 of a pie)? in case you want pie, you'll likely make the first selection, and that is because 2/3 is larger than 3/8. as a effect 3/8 < 2/3. the maths thanks to do it truly is to multiply the left facets by 3/3 and the right part by 8/8 (both are fancy methods of writing a million). then you definitely have 9/24 on the left part and 16/24 on the right part. Now the decision on the bottom is an similar and it truly is a lot a lot less annoying to guage; obviously 9/24 < 16/24. In different words, you're cutting the pie into 24 products; 3/8 of the pie is an similar as taking 9 products, and a couple of/3 of the pie is an similar as taking 16 products.

Answer 5

Circumference (C) = diameter (d) x pi,
Area (A) = radius x radius x pi
diameter = radius x 2
1. C= 8 x 3.14 or 25.12, A= 16 x 3.14 or 50.24
2. C=11 x 3.14 or 34.54, A=30.25 x 3.14 or 94.99
3. C=5.2 x 3.14 or 16.33, A= 6.76 x 3.14 or 21.23
I hope this answers your question.

Answer 6

Circumference area = phi (3.14) x radius ^ 2

1) 4cm radius: area = 4cm^2 x 3.14 = 16 cm2 x 3.14 = 50,24 cm2

2) 5.5 cm radius: area = 5.5cm^2 x 3,14 = 30.25cm2 x 3.14 =
= 94.985 cm2

You don't give the unities for nº 3). Lets suppose cm. Then:

3) 2.6cm radius: area = 2.6^2 x 3.14 = 6.76cm2 x 3.14
= 21.226 cm2

The greatest one is nº 2) 94.985 cm2
The middle one is nº 1) 50.240 cm2
The smallest one is nº 3) 21.226 cm2

Answer 7

1) 25.12

2) 34.54

3) 16.32

In order to find circumference you multiply the diameter of the circle by pie(3.14). In order to find the diameter you multiply the radius by 2.

Answer 8

First off,
AREA: a = pi*r^2 (r for radius)
CIRCUM: c = pi*d (d for diameter)
d = 2r
pi = 3.14 as u wanted

1)
c = pi * 8 = 25.12 cm
a = pi * 4^2 = 50.24 cm^2
2)
c = pi * 11 = 34.54 cm
a = pi * 5.5^2 = 94.99 cm^2
3)
c = pi * 5.2 = 16.33 cm
a = pi * 2.6^2 = 21.23 cm^2

the end

Answer 9

circumference=2(pie)(radius)

1. c=2(pie)(4cm)
c=25.132741cm

2. c=2(pie)(5.5cm)
c=34.55751cm

3. c=2(pie)(2.6cm)
c=16.3362818cm

Answer 10

Heres the equation R is for radius
Circumference=2R x 3.14
Area=R squared x 3.14
Correct me if im wrong