Question

When two congruent equilateral triangles share a common centre, their union can be a star, as shown. If their overlap is a regular hexagon with an area of 60 sq.units, what is the area of one of the original equilateral triangles? Select one: a. 60 sq.units b. 30 sq.units c. 90 sq.units d. 120 sq.units ​

Answer 1

That will be  90 sq units....  

The overlap is a regular hexagon and is divided into 6 equal triangles at the center.  Each small triangle = 10 sq units.
 
Then, there will be a total of 9 equilateral triangles (small) inside the given  equilateral triangles.  So then total area of 9 triangles = 9*10 sq units.