Helena is an engineer that designs packaging for new products. She designed a box in the shape of a rectangular prism with dimen
sions of 10 inches by 7 inches by 4 inches. What is the surface area of the box? a.138 square inches
b.276 square inches
c.280 square inches
d.441 square inches
B is the answer 10x7= 70 (Base 1) 10x7= 70 (Base 2) 10x4= 40 (Front) 10x4= 40 (Back) 7x4= 28 (Side 1) 7x4= 28 (Side 2) --------------------------------- SA= 276 Remember to think of a rectangular prism as a box, then label the base, the width, and the height :)
Since we don't know the distance from C to B, we can label it as x. Our equation will be x+(x-3)=18. Simplify that so it is 2x-3=18. Add 3 to both sides and get 2x=21. x=10.5 So AC=7.5 cm and CB is 10.5 cm
