Tuesday

October 21, 2014

October 21, 2014

Posted by **G** on Friday, February 15, 2008 at 10:59am.

A=area of a trapezoid

b1=width at the top

b2-width at the bottom

h=height

A 7-foor tall trapezoid has 42 square feet of area. If is is 9 feet wide at the bottom, how far across is it at the top?

- Algebra -
**Guido**, Friday, February 15, 2008 at 11:05amI will set it up for you and you can simplify.

A = 42

h = 7

b2 = 9

I will plug and you can chug.

42 = 1/2(b1 + 9)(7)

Solve for b1, which is read "b sub one."

Can you take it from here?

- Algebra -
**G**, Friday, February 15, 2008 at 11:09amThank you for your response. I can set up and calculate. The book says I should be getting 3 feet as my answer. That is not what I am getting.

- Algebra -
**Guido**, Friday, February 15, 2008 at 11:13amHere it is:

First multiply 7 x 1/2 = 7/2.

We now have this equation:

42 = 7/2(b1) + 9)

Simplify the right side of the equation and the whole thing becomes

42 = 7/2(b1) + 63/2

Subtract 63/2 from 42.

42 - 63/2 = 10_1/2

We now have:

10_1/2 = 7/2(b1)

10_1/2 divided by 7/2 = b1

3 feet = b1

Done!

- Algebra -

- Algebra -

**Answer this Question**

**Related Questions**

algebra - sooo confusing... 6. (¼ + 7/8)(9/13) A81/13 B17/104 C81/104 D17/29 E17...

Algebra - Trapezoid. Height is 16m, one base is 2 20m, and the area is 224 m ...

algebra - a1. Simplify 5 + (7-1)2/6 A11 B41/6 C51/6 D7 E17/6 F23 b2. Simplify (...

algebra - The formula for the area of a trapezoid is A = h(B + b) 2 . The area ...

calculus - A water-trough is 10m long and has a cross-section which is the shape...

geometry help - a trapezoid has base lengths of 4 and 19 feet, with an area of ...

Geometry - I missed this problem on my test. I had 23 ft and the correct answer ...

Geometry - 1. What is the base and the height of the rectangle if the area is ...

math - how do you calculate the area of a trapezoid the has the base of 11.25 ...

geometry - The trapezoids are similar. The area of the smaller trapezoid is 564m...