It is given:Alexis has a piece of red paper that is 4 centimeters wide. Its length is twice its width .If length is 4cm then width = 4x2= 8cm.
Area of red paper= length x width = 4x8=32 square cm.
Alexis glues a piece of blue paper on top of the red piece measuring 3 centimeters by 7 centimeters.
Area of blue paper= 3x7=21 square cm.
Area of red paper that will be visible on top =32-21= 11 square cm.