3) find the area of just the wood portion of the frame. this is called a composite figure

Area of rectangle is given by:
Area=length*width
area of the composite figure will be given by:
area=(total area of the frame plus picture)-(area of the picture)
total area of the frame plus picture is:
Area=length*width
=5×7
=35 in²
area of the picture will be:
Area=4×6
=24 in²
therefore the area of the composite figure will be:
Area=35-24
=11 in²