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6 votes
6 votes
Good morning I really need some help with this problem please!

Good morning I really need some help with this problem please!-example-1
User Ralf Wagner
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2.9k points

1 Answer

5 votes
5 votes

On the plane

Therefore, AB and DC are parallel sides, and so are BC and AD.

We need to calculate the length of 2 perpendicular sides, for example, AB and BC.

In general, the formula to get the distance between two points is


\begin{gathered} (x_1,y_1),(x_2,y_2) \\ \Rightarrow d=√((x_1-x_2)^2+(y_1-y_2)^2) \end{gathered}

Thus, in our case,


d(AB)=√((-3+2)^2+(1+1)^2)=√(1+4)=√(5)

and


d(BC)=√((-2-2)^2+(-1-1)^2)=√(16+4)=√(20)

Therefore, the area is


\begin{gathered} \Rightarrow A=d(AB)*d(BC)=√(5)*√(20)=√(5*20)=√(100)=10 \\ \Rightarrow A=10 \end{gathered}

Thus, the area is 10, option B.

Good morning I really need some help with this problem please!-example-1
User Jesferman
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3.0k points