one side of a polygon is 20ft. find the corresponding of a similar polygon with corresponding sides of the first polygon 3ft.to the second polygon 9ft. What is the ratio of their perimeters?

Question

anonymous · Answer

@mads4566 , 
The ratio of corresponding side of 1st polygon and 2nd polygon
$$={{3}\over{9}}={{1}\over {3}}$$

Now , in the question we know  a side of first polygon, then how wll you find the side of 2nd polygon, @mads4566 ??

anonymous · Answer

*will

anonymous · Answer

cross multiply of some sort...

anonymous · Answer

Yes. Tell me what according to you would be the corresponding side for 2nd polygon, given 1st polygon side is 20 ft??

anonymous · Answer

Assume
1st polygon side =1 ft ,  then 2nd polygon side would be = 3ft
Now
1st polygon side =20 ft ,  then 2nd polygon side would be = ?

anonymous · Answer

60

anonymous · Answer

Exactly.

anonymous · Answer

Now what do you think will be the ratio of their perimeters??

anonymous · Answer

i was half way thru a test and my computer shut down :'( idk what problem tht is anymore

anonymous · Answer

ahha yea i have no idea

anonymous · Answer

i feel rather stupid. I should know how to do this but it just doesn't make sense!

anonymous · Answer

oh my goodness ... my aunt used my computer and exited my test ... i failed :'( i wasn't even 2/3 of the way done with it UGH!!!!

anonymous · Answer

See I will give you a tip:

You know the ratio of 2 sides. (see 1st post of mine)  

You also know 2 sides of each polygon.  Now add the length of 2 sides of each polygon and take their ration now. Tell me what ratio do you get ??

anonymous · Answer

*ratio

anonymous · Answer

ok so 1/3 and and 20/60?.... 2/6....1/3... no wait i already have tht one .... im confused

anonymous · Answer

No I am asking you for this

(20+3)/(9+60) = ??

anonymous · Answer

1/3

anonymous · Answer

Yes.  You took the individual side ratio of the 2 polygon , you ended up with 1/3/
Then you took the ratio of sum of 2 sides of polygon,  you again ended with 1/3.

Now tell me what do you expect the ratio of the perimeters of the 2 polygon to be ??

anonymous · Answer

1/3

anonymous · Answer

yes. :)

anonymous · Answer

yay ... if only i could have finished my test :(

anonymous · Answer

No problem.  Just remember, there is always an another chance in life :D

anonymous · Answer

.. very optimistic if you..... thnx for the help lol

anonymous · Answer

Lol..:D  Welcome :D