Question 1139795

his shape is made of square and rectangle. 
rectangle has same width as the square but it is twice as long

let dimensions of the square be {{{a}}}
let dimensions of the rectangle be {{{a}}} and {{{b}}}
given that {{{b=2a}}}

area of the shape: area of the square plus  area of the rectangle

{{{A=a^2+a*2a}}}
{{{A=a^2+2a^2}}}
{{{A=3a^2}}}

given: {{{A=75cm^2}}}

find dimensions:

{{{3a^2=75cm^2}}}

{{{a^2=75cm^2/3}}}

{{{a^2=25cm^2}}}

{{{a=sqrt(25cm^2)}}}

{{{a=5cm}}}

=>{{{b=10cm}}}

  the perimeter of the shape is:  perimeter of the square plus  perimeter of the rectangle

{{{P=4a+2(a+b)}}}

{{{P=4*5cm+2(5cm+10cm)}}}

{{{P=20cm+30cm}}}

{{{P=50cm}}}