solve the formula for area of a trapezoid. A = h(b1 + b2/2) for b1

Question

diyadiya · Answer

$$A= h( \frac{b1+b2}{2})$$first multiply both sides by 2 
can you do that?

apoorvk · Answer

You mean:
$$A = h(\frac{b_1 + b_2} 2) $$

where $b_1~ and~b_2$ are length of parallel sides, and 'h' is the height right?

Can you just rearrange the whole thing, to write it in terms of $b_1$ solely?

anonymous · Answer

That is what I meant.

apoorvk · Answer

I mean, to write it *implicitly* for $b_1$.

diyadiya · Answer

$$2 \times A = 2 \times h \left( \frac{b1+b2}{2} \right)$$$$2 A = \cancel{2} \times h \left( \frac{b1+b2}{\cancel{2}} \right)$$$$2 A = h \left( {b1+b2} \right)$$

Can you continue from here?

anonymous · Answer

yeah thanks.

anonymous · Answer

I mean it's still kind of confusing..

diyadiya · Answer

Welcome!! 

But what will be the next step?

anonymous · Answer

well the answer is for b1

anonymous · Answer

I have no clue :(

diyadiya · Answer

lets go step by step though

did you understand till this part?

anonymous · Answer

yeah pretty much

diyadiya · Answer

Sure?

diyadiya · Answer

Please do ask if you haven't got any specific step!

anonymous · Answer

yes

anonymous · Answer

I get it to this part.

diyadiya · Answer

ok so,

2A = h(b1 +  b2)

Now next step is to divide both sides by 'h'

can you do that?

anonymous · Answer

is it b1 = a/h?

diyadiya · Answer

Nope, don't be in a hurry! do the step i told you to do :)

anonymous · Answer

okay okay :P

diyadiya · Answer

??

anonymous · Answer

yeah I can only do so much for an 8th grader lol

anonymous · Answer

Im in an advanced math and i'm horrible at it.

diyadiya · Answer

Its just division just divide both sides by h 

for example when you have c = bk  and when you divide both sides by k you get 
c/k = bk/k 
c/k = b

just like that!
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