Find the surface area of an open box with length of 12 inches, width of 7 inches, and height of 4.5 inches

Also, Good Moring
Worth 20 points

Step-by-step explanation:

l = 12 inches

w = 7 inches

h = 4.5 inches

Surface area = lw + 2wh + 2hl

                     = 12*7 + 2*7*4.5 + 2*4.5*12

                    = 84 + 63 + 108

                    = 255 square inches

If it is a closed box, surface area = 2*(lw +wh + hl)

As it is open, surface area = lw + 2wh + 2hl

Down part of the box : length *width

Upper part of the box = length*width

So, for closed box, 2lw

For open box , lw

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.