Right: Area:10×10-5× 3 =100-15 = 85 Perimeter:10+10+.

5. Cut the largest square in the rectangle, and the side length of the square is the width of the rectangle. The length and width of the other small rectangles are 6 cm and (8-6) cm respectively, and the area is (8-6) × 6 = 12 cm2.