We need to calculate the surface area
We have 6 faces and three different rectangles
The red rectangles are equals
The green rectangles are equals
The blue rectangles are equals
The formula for the area of a rectangle is
where
l is the length
w is the width
The area for one red rectangle
l=10
w=5
The area for one green rectangle is
l=10
w=7
The area for one blue rectangle
l=7
w=5
The total area is
Then we need to transform the square inches to square feet
1 square ft = 144 square inches
x square ft = 310 square inches
Mrs Harris will need 2.15 square ft to wrap the prism