Help with ALGEBRA??

Question

A = ½ h (B + b) (for b) Area of a trapezoid

I am not understanding this, please someone help.. Thank you in advance.

Answer 1

The area of a trapezoid is one-half the height times the two bases added together. For example if i have a trapezoid that is 5 cm high, and has bases of 4 and 6 cm, the area is (.5)(5)(4+6)=25 square cm

Answer 2

Well technically this geometry and not algebra, but here goes:

A trapezoid consists of two horizontal parallel lines connected by two non-parallel vertical lines
In this formula:
A is the area of the trapezoid
h is the height of the trapezoid (the distance between the two parallel lines)
B is the length of the longer parallel line
b is length of the shorter parallel line

To get the area, multiply the height by 1/2 (or divide it by 2, whichever's easier for you), then multiply the product of that by the sum of the lengths of the two parallel lines (B + b)

Let's say you have a trapezoid whose height is 4 inches (h = 4), and whose parallel lines are 3 and 4 inches (B = 4, b = 3). To get the area you add B and b (3 + 4 = 7) then multiply that by 1/2 the height (4/2 = 2). 2 x 7 = 14, so your trapezoid has an area of 14 square inches.

Answer 3

do you know what all the variables stand for?

h is the height measuring straight from the top to bottom

b and B are the two flat parallel bases


to understand the formula think of a trapezoid as a messed up rectangle. rectangle area is b*h right? trapezoids are pretty much the same, except they have a little b and a big B because the top and bottom arent the same size. all youre doing is taking the average of the two bases (this formula only works for symmetrical trapezoids, which most of them are so dont worry too much about that). anyway, we were talking about the average of the bases. no problem- add them up and divide by two. thats where the 1/2 in the equation comes from. think of it as going with the (b+B) instead of with the h. that accounts for the base, then you just multiply by the height, like you would for a normal old rectangle

i hope that helps, if you still have a question just send me a message! :)

Answer 4

You know that to find the area of a square you multiply the base by the height.

It's essentially the same thing here, except that you don't know what the base is, so you have to find the average of the length of the top side and the length of the bottom side.

Obviously if the lengths were 7 and 9, then you would know the average is 8, but if it's not as straightforward as that then you add the two numbers together and halve them (7 + 9 = 16; 16 / 2 = 8). Then you multiply by the height.

I hope this helps.

Answer 5

Firstly what is a Trapezoid ?
A trapezoid is a Quadilateral with 2 sides parallel.

Okay, Area of Square or rectangle is Length x Breadth.
Applying the same concept for Rectangle BUt since a Traapezoid only has one side parallel.

Its the formula for Area of Trapezoid = 1/2 x (Sum of length of parallel sides) x
the perpendicular height (breadth)

In your question B and b are the parrallel sides. h is the perpendicular length from B to b.

Got it ?

isz_rossi
Singapore

Answer 6

Ok that's the formula for the area of a trapezoid.

The 'B' is the value for the length of one of the long sides, and the 'b' is the value for the length of one of the smaller sides, I believe. Now if you're solving for the little b, you first have to get everything but the (B+b) to the other side. You can probably figure that part out if you think carefully.

You're multiplying by 1/2 for starters, so you have to divide by 1/2 (or multiply by 2), so that gives you 2A = h(B+b).

Then you're multiplying by h, so you have to divide by h on both sides, so you get 2A/h = B +b.

Then after that you have just B+b on the right side, and to get the little b, you subtract the big B from both sides. I hope that answers your question (I assumed that by "for b" you meant that the question was asking you to solve for b).

Answer 7

If the base is 12 and the height is 16 multiply the two numbers. Then multiply that number by 1/2

Answer 8

B and b is the length of top and bottom of trapezium....get the same shape trapezium and invert it and stick it to the original you will get a parallelogram...and you x height which forms a rectangle if you cut the left part of the triangle to stick it to the right or vice versa same thing and since its a single trapezium but you made a double you x half.....its hard to explain in words but easy in diagram...ask you teacher to show you in school if you still dont get it...all the best

Answer 9

the area of the trapezoid equals one half times the height of the trapezoid multiplied by the bottom and top lengths added together. To solve for b, b= [A/(.5h)] - B

Answer 10

The abbreviations mean

Area = 1/2 multiplied by the measure of the height of the trapezoid (A line that is perpendicular to the bases) multiplied by
(the bases added together, you add them together, then multiply the product because it is in parenthesis)

Tada! there you have it