The perimeter of a square is given by #P=4sqrtA# where A is the area of the square, determine the perimeter of a square with the area 225?

1 Answer
May 23, 2017

#P=60" units"#

Explanation:

Note that #5xx5=25#. The last digit of which is 5

So what ever we have to square to get 225 will have 5 as a last digit.

#5^2=25 color(red)(larr" Fail")#

#10 color(red)(rarr" cant use as it does not end in 5")#

#15^2->15(10+5)=150+75=225color(green)(larr" This is the one")#

Thus we have:

#P=4sqrt(225)#

#P=4xx15=60#

but to be mathematically correct we should include the units of measurement. AS these are not given in the question we write:

#P=60" units"#