Question 100465
The area of a square is equal to one of its sides squared
OR
{{{A=S^2}}}
This problem states that if the sides of a square are increased by 5 the area becomes 289
so lets plug that information into the formula for area of a square
{{{A=S^2}}}
{{{289=(s+5)^2}}}
now just solve for s
first take the square root of both sides of the equal sign
{{{sqrt(289)=sqrt((s+5)^2)}}}
{{{17=s+5}}}
{{{12=s}}}
so the sides of the original picture frame are 12 cm
Check answer
{{{289=(s+5)^2}}}
{{{289=(12+5)^2}}}
{{{289=(17)^2}}}
{{{289=289}}}
done!