# Quadratic Formula and sovling a Word Problem

• March 17th 2008, 06:28 AM
JohnMon
Quadratic Formula and sovling a Word Problem
I need some help on sovling this word problem using Quadratic Formula. Well, I can sovle it I just need help finding the a,b and c of the formula.

"As a factory group leader, you are to facilitate the building of hinge plates for a special application of the “Help Rebuild New Orleans” foundation. Your boss gives you a few restrictions: The trapezoidal plate must have a height three inches greater than its primary base and, the ratio of the secondary base to the primary base is six tenths. If the budget only allows you 4800 in3 of ¼” stock sheet metal, what are the dimensions of each plate?"

My teacher messed up it was changed to what is in red down below I am sorry for being so confusing.

"As a factory group leader, you are to facilitate the building of hinge plates for a special application of the “Help Rebuild New Orleans” foundation. Your boss gives you a few restrictions: The trapezoidal plate must have a height three inches greater than its primary base and, the ratio of the secondary base to the primary base is six tenths. If you are to make 1200 plates and the budget only allows you 4800 in3 of ¼” stock sheet metal, what are the dimensions of each plate?"

I see were the 4800 comes from now.

Thank you bunches!
• March 17th 2008, 07:03 AM
galactus
If I am reading correctly, the primary base has length p, while the height must have length p+3. The secondary base would have length 3p\5.

The trapezoid formula is $\frac{\frac{3p}{5}+p}{2}\cdot{(p+3)}=4800$

Solve for p(the primary base) and the rest will follow.
• March 19th 2008, 06:41 AM
JohnMon
Thanks
Thanks galactus for helping find the area of the trapezoid even though the next class he told us it was a mistake on his part. makes sense because its not a Geometry class.

Thanks Soroban for the email.