What construction does the image below demonstrate?
a. an equilateral triangle circumscribed about a circle
b. an equilateral triangle inscribed in a circle
c. the circumcenter of an equilateral triangle
d. the incenter of an equilateral triangle

An equilateral triangle inscribed in a circle  

Step-by-step explanation:

A. An equilateral triangle circumscribed about a circle

 equilateral triangle circumscribed about a circle mean a circle inside an equilateral triangle. We don't have circle inside the triangle in our graph.

B. An equilateral triangle inscribed in a circle  

Yes equilateral triangle is inscribed in a circle BDE

C. The circumcenter of an equilateral triangle

Circumcenter is not equidistant from the vertices of triangle

step-by-step explanation:

in the absence of parentheses, i will have to make some assumptions:   i interpret your (3x+5/y^6)(4y^3/5)​ to mean:

3x + 5     4y^(3/5)       (3x + 5)(4)

* =

    y^6             1               y^(6-3/5)

if this is not what you expected, repost your question using parentheses to indicate whether you meant

4y^3

    or   4y^(3/5)

    5