Posted by Ariel on .
In a rhombus, one diagonal has a length of 10 cm and the area is 120 cm2. Find the length of one side.
a.)10cm
b.)12cm
c.)13cm

Geometry HELP 
drwls,
A rhombus has equal side lengths. The two intersecting diagonals create four congruent right triangles of area 30 cm^2 each.
Let side length = a
30 = (1/2)*5* sqrt(a^2 5^2)
12 = sqrt(a^2 25)
144 = a^2 25
a^2 = 169
a = 13
The length of the other diagonal is
2*sqrt[(13^2  5^2)] = 24 cm
Interesting problem! 
Geometry HELP 
Ariel,
This is an interesting problem:) Thanks!!