Question 934038
Let's assume the classroom the statement is referring to is a rectangle.
The perimeter of a rectangle can be determined by 
{{{ P = 2L + 2W }}}
Since we know that the perimeter is 24, we can apply this to our equation.
{{{ 24 = 2L + 2W }}}
Since the width is 1 meter more than 1/4 of its length we can assume that
{{{ W = (1/4)L + 1 }}}
Because we know the width, we can plug-in the value of W into the first equation and can solve.
{{{ 24 = 2L + 2((1/4)L + 1) }}}
{{{ 24 = 2L + (1/2)L + 2 }}} Distribution Property
{{{ 24 = (5/2)L + 2 }}} Combine Like Terms
{{{ 24 -2 = (5/2)L + 2 - 2 }}} Subtraction Property of Equality
{{{ 22(2/5) = (5/2)L(2/5) }}} Multiplication Inverse or Reciprocal
{{{ 8.8 = L }}}
The length is 8.8!