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Let's do this question, find the area of the quadrilateral whose vertices are zero zero seven nine,

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10, eight and 12, comma six.

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All right, was the video.

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Give it a try and then let's do it together.

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Now, you can either take it as two triangles and then solve it, or you can also to solve it using

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this formula that is you write the vertices in this manner, you put half over here, then you have

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x1 y one extra Y two x three y three X for Y four and then you have again X and Y one.

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And then it's the same method.

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You multiply one by one by two x2 and Y three x three and four X and Y one.

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Similarly you do this operation also that is x2 and Y one x3 and Y to x4 and Y three and X one and rifle.

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Right.

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And then you take the difference.

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Let's apply it over here.

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You have zero zero seven, nine, ten, eight and 12 six and then you cross multiply over here zero

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into nine plus seven into eight plus ten in the six plus twelve in the zero.

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That gives you one hundred and sixteen.

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Right.

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OK.

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And seven to zero then in the nine plus twelve in the eight plus zero in the six that gives you one

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eighty six.

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Right.

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Therefore the A's have in two one one six minus one eighty six and you always take the positive value

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but that's seventy divided by two and that gives you the answers.

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Thirty five units square.