Find the area of the rectangle

Question

Find the area of the rectangle whose vertices are (2/5,2) (2/5,-1) (0,2) ( 0,-1) 

 

Hi, I've tried so many times to get the right answer but I keep getting a crazy decimal number. The correct answer is 6/5 and I can't seem to get to it. I dont know of I'm calculating something wrong but I know the distance formula and plugged the right values in so I'm pretty sure I messed up in the calculation. 

Answer 1

 

Take the first two vertices: (2/5,2), (2/5,-1). They define the right side of your rectangle. The length of this side is 

2 - (-1) = 3.

 

Take the other two vertices: (0,2), (0,-1). They define the left side of the rectangle, which is parallel to the previous one. Its length is also 2 - (-1) = 3. 

 

So, the height of the rectangle is 3.

 

Now, you do the same to find the length of its base.

 

Take the two vertices (0,-1), (2/5,-1). They define the lower side of the rectangle. Its length is 2/5 - 0 = 2/5.

 

Take the other two vertices: (0, 2), (2/5, 2). They define the upper side of the rectangle. Its length is 2/5 - 0 = 2/5.

 

So, the length of the rectangle's base is 2/4.

 

Hence, the rectangle's area is 3 x 2/5 = 6/5.