HELP IN MATH PLZ !!!

[seif9000]

HOW CAN I GET THE LOWER BOUND OF PERIMETER OF THE SQUARE THAT HAS SIDE LENGTH 6.81 CORRECT TO 3 SIGNIFICANT FIGURES ????
PLZ I NEED HELP AND THNX
(I AM IN MATH EDEXCELL BUT THERE IS NO ONE ANSWERING ME IN THE OTHER FORUM)

 

[XPFMember]

remember always first u should find the bounds and then do any multiplication...
now in this question it is 6.81 rounded to 3 s.f,so see at the third significant fig. whats its place value,it is 0.01 (or 1/100) so smallest unit of measurement will be 0.1 and hence absolute error will be 0.1/2 = 0.05.Lower bound=6.81-0.005=6.805
perimeter= 4Xlength =4X6.805=27.22,thats it ,also remeber u DO NOT have to round any number in such questions,always give the full calculator display!!
hope this helped!

 

[seif9000]

thank you for your help but i want to ask, what number is the first s.f is it the 8 or it is the 1 , if it is the 1 so its place should be 0.01 and if it was the8 then why we chose the 8 not the 1, i hope you understand my question and i would like to thank you for this help math angel please reply ?!!!

 

[XPFMember]

oh i am sorry ,i did a mistake well it is not 0.01 not 0.1 really really sorry!!!

 

[seif9000]

no problem and thnk you very much for your help

 

[XPFMember]

I editted my post,btw thanks for telling!and the 1st significant fig. is 6!

 

[seif9000]

your the best i swear , thnx

 

[XPFMember]

may Allah grant us success in the HereAfter too as well as in this world Aameen!