Question 1063529
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The angles of this rhombus are 60° and 120°, which is obvious.


Hence, the shorter diagonal divides it in two equilateral triangles with the side length of 20 units each.


Then the perimeter of the given rhombus is 80 units.


On properties of rhombis, see the lessons

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/Parallelograms/Diagonals-of-a-rhombus-are-perpendicular.lesson>Diagonals of a rhombus are perpendicular</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/Parallelograms/Diagonals-of-a-rhombus-bisect-its-angles.lesson>Diagonals of a rhombus bisect its angles</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/geometry/How-to-solve-problems-on-the-rhombus-sides-and-diagonals-measures-Examples.lesson>HOW TO solve problems on the rhombus sides and diagonals measures - Examples</A> 

in this site.