Question

how calculate height of trapezoid without area? Or how calculate the area if I have B b and two diagonals?

Answer 1

base and two diagonals?

Answer 2

I have two bases and two diagonals? what formula I can use to calculate the area?

Answer 3

Can you find the height based on the given information?

Answer 4

Find the area of trapezoid with bases 7cm and 20cm and diagonals 13cm and 5\[\sqrt{10}\]

Answer 5

this is all information which I have in problem

Answer 6

One more hint, do you know what is the median of a trapezoid?

Answer 7

yes, of gourse (B+b)/2; (20+7)/2=13.5cm

Answer 8

I think I have a solution but it's a bit ugly,

#1 Use this ( http://en.wikipedia.org/wiki/Trapezoid#Properties ) formula to find the the other two non-parallel sides of the trapezoid.

#2 Find the height using this \[ h= \frac{\sqrt{(-a+b+c+d)(a-b+c+d)(a-b+c-d)(a-b-c+d)}}{2(b-a)} \]

\( a\) and \( b\) are parallel sides and \(c\) and \( d\) are non-parallel sides.

#3 Now you can find the area.

Answer 9

But if it's given that that the diagonals intersects at right angle then you can simply find the area as \(\frac 12 \times\) product of the diagonals

Answer 10

Thanks you much FoolForMath. But without length of non-parallel sides, or without height I can't find area. Maybe is another way to solve.