1. Multiply 5 by 2 since the piece is twice as long. That is 10. Multiply 4 by 3 since the piece is 3 times as long. That is 12. Her piece is 10 x 12. 2 sides of 10 & 2 sides of 12. Multiply 10 & 12 by 2 to get 20 and 24. Add them together to get 44 inches, which is the perimeter.
2. Multiply 4 x 2 since length is twice width. That is 8. Multiply 8 x 4 to get the area of the red paper. That is 32. Multiply 3 x 7 to get the area of the blue paper. That is 21. Subtract 21 from 32 to get the amount of red paper that wasn't covered up. 11 square cm were not covered up.
