Answer:
Side of bare canvas = 17 cm
Step-by-step explanation:
Let the original side of square shape canvas painting be x cm
Adding 4 cm wide decorative frame to each side of the canvas.
The area of of frames painting is 625 cm²
Please find the attachment for figure.
Frame added both sides. New side = (x + 4 + 4)
The new side of painting after added frame = (x + 8) cm
The shape of painting is square.
Area of square shape = side × side
Therefore,
[tex](x+8)(x+4)=625[/tex]
[tex](x+8)^2=25^2[/tex]
Taking square root both sides
[tex]x+8=25[/tex]
[tex]=x=25-8[/tex]
[tex]x=17[/tex]
Hence, the side of the bare canvas is 17 cm
