Question

http://prntscr.com/b3fudo
I'm having issues with these four questions.

I know to use them I have to use these v
http://prntscr.com/b3fvb8
http://prntscr.com/b3fvgl
And circumference =diameterxpi or 2pidiameter

I'm just having a hard time applying them.

Answer 1

Circumference (C) = pi*diameter = 2*pi*radius
7 is very straightforward, can you tell me what numbers to put in the equation for this problem before we tackle the tougher ones?

Answer 2

@mjdennis

Arc=0.4 ciir=25.12?

Answer 3

Good, you are on the right track. The arc is not just 0.4 though; it is 04 _of_the_circumference. (I cannot tell if gray is the 144° part.) Read the problem statement again, and leave pi as a symbol instead of substituting 3.14.

Answer 4

I got 10 for arc length because diameter=8

Answer 5

8: find the circumference of the wheel. Since one rotation makes the wheel travel 1 circumference of road, x rotations will cover x circumferences of roads. How many times does the circumference go into 1 km?
9. Make sure you know the radius and your formula will work.
10. The 'slice' is the sector with a triangle subtracted. I'm pretty sure you can make the triangle out of two identical right triangles you know how to solve.

Answer 6

Back to 7a: r=4 and d=8, yes.
So C = pi*d = 8*pi, not 10
7b. Arc is 144/360 * C, right, which is 0.4*C
rest is up to you.

Answer 7

I'm confused. I'm using this formula
http://prntscr.com/b3g68i

And I got 10 again.

Also, I would need your help working with the other three questions.

Answer 8

@mjdennis

Answer 9

which problem are you on again? problem 7 part a? or have you moved on?

Answer 10

Problem 7
@jim_thompson5910

Answer 11

part a? or b?

Answer 12

Part b

Answer 13

ok I'm assuming they want the dark gray arc. They used two different types of gray here.

Answer 14

what was your answer to part (a) ? that will be used to answer part (b)

Answer 15

25.12 for a

Answer 16

Leave your answer in terms of pi

Answer 17

Example: if the diameter is 12, then the circumference is 12pi

Answer 18

8pi

Answer 19

yep that's the answer to part (a)

Answer 20

now you'll multiply that with (144/360) to get the piece of the curve

Answer 21

0.4?
@jhonyy9

Answer 22

144/360 = 0.4

0.4*8pi = 3.2pi

so the whole circumference is 8pi (answer to part a)
the arc is 3.2pi (answer to part b)

Answer 23

Got it! Alright, what about the next three questions.

(Want me to open another thread or)
@jim_thompson5910

Answer 24

`Want me to open another thread`
yes please. One thread per question