10× 10= 100 (square centimeter) This is the area of a big square.
(10-3)×( 10-3)=49 (square centimeter) This is the area of a square.
100-49=5 1 (square centimeter) This is the area of this graph.
There's another way.
10×3×2=60 (square centimeter) This is the area of two rectangles.
3×3=9 (square centimeter) This is the overlapping part.
60-9=5 1 (square centimeter) This is the area of this graph.
Perimeter: Perimeter is simpler.
10+ 10=20 (cm) This is the circumference of the outside.
(10-3)+(10-3) =14 (cm) This is the perimeter inside.
20+ 14=34 (cm) This is the perimeter of the graph.
I hope the above can help you!