Question

ABCD is a rectangle whose length AB=3x+2,breath BC=Y-2,CD=X+10,DA=3Y-10 then find the length of the diagonal

Answer 1

hope it helps you.....
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Answer 2

from rectangle's property
AB should equals to CD , hence
3X+2=10X+4.......(1)
from here..
X=4.

similarly
BC=AD..

Y-2= 3Y-10......(2)
gives
Y=4.

X And Y are the sides of the rectangle, hence
$\sqrt{x { } ^{2} + y { }^{2} } = digonal$
or diagonal is
$4 \sqrt{2}$