Question

Perimeter and area of a rhombus??? Please help!!!

http://tinypic.com/r/x40yaa/5

So, I know the parallelogram is a rhombus, but I don't understand how to find the perimeter and area of it. Can someone please help me?

Answer 1

do you know distance formula ?

Answer 2

you can find distance AB since you have the co-ordinates of A and B

Answer 3

Distance between points (x1,y1) and (x2,y2) is
\(\huge d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}\)

Answer 4

So...The distance between them is...5.38, right?

Answer 5

YES :)
and BC = ...?

Answer 6

Is the same thing? 5.38?

Answer 7

oh, oops , yes, you said its rhombus
then whats AD =CD = ... ?

Answer 8

Uh...I'm not sure...how do you find that?

Answer 9

a rhombus has all sides equal, all are 5.38 .
ok, so perimeter = 4* 5.38

Answer 10

Ahh, okay, so then the perimeter is 21.52 then. What about the area?

Answer 11

find the lengths of diagonals
AC =
BD =
then area = AC*BD /2

Answer 12

how do I find the lengths of the diagonals?

Answer 13

you have the co-ordinates of A and C
use the distance formula to find AC

Answer 14

Okay, give me a sec...

Answer 15

would it be 4.24?

Answer 16

YES!
you can keep it as 3 \(\sqrt 2\)

BD = ... ?

Answer 17

would it be 9.89?

Answer 18

YES!
you can keep it as 7\(\sqrt 2\)
now find the area

Answer 19

area = AC*BD /2

Answer 20

So then, the area is 20.9668 units?

Answer 21

to be accurate its 21 :)

Answer 22

Ah, okay! Thanks sooooooooooo much for the help! I really needed it. And, I learned something new! :D

Answer 23

i'm glad to hear that! :)
you're most welcome ^_^