find difference in distances in going around inside, outside

[anakbongsu]

the diagram shows a running track with the 'straights' 90m ling and with semicircular end sections.if the inside distance is 400m and the track is 8m wide, how much further is it to run around the outside of the track?

 

[mmm4444bot]

Re: PLEASE HELP ASAP!!!

Start with a better diagram.

My diagram shows the inside edge of the track.

We know its perimeter.

Can you see the following strategy (steps)?

Calculate r

Increasing r by 8 gives the outside edge of the track

Calculate the outside perimeter using r + 8

Calculate the difference.

If you get stuck in any of the calculations using the formulas, or setting up equations, then please post what you've been able to do so far and explain why you're stuck.

Cheers,

~ Mark