SOLUTION: The amount of paper needed to cover a box top in the shape of a trapezoid is 198cm squared.if the height of the box top is 18cm and the length of one of the bases is 10cm,find the

Algebra ->  College  -> Linear Algebra -> SOLUTION: The amount of paper needed to cover a box top in the shape of a trapezoid is 198cm squared.if the height of the box top is 18cm and the length of one of the bases is 10cm,find the       Log On


   

Question 896837: The amount of paper needed to cover a box top in the shape of a trapezoid is 198cm squared.if the height of the box top is 18cm and the length of one of the bases is 10cm,find the length of the other base.
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
length of the other base is 12.

area of a trapezoid is equal to 1/2 * h * (b1 + b2)

h = 18
b1 = 10
b2 = 12

area = 1/2 * 18 * (22) = 9 * 22 = 198

you solve by plugging what you know in the formula and then solving for what you don't know.

you know that area is 198 and height 18 and one of the bases is 10.

formula becomes:

198 = 1/2 * 18 * (b1 + 10)

simplify to get 198 = 9 * (b1 + 10)

divide both sides by 9 to get:

198/9 = b1 + 10

subtract 10 from both sides to get:

198/9 - 10 = b1

solve for b1 to get b1 = 12.