The answer is D.
Assuming this is the apex question.
Solution
The diagram below will be of help
Note: Area of a Sector Formula
Here
Substituting the parameters
There are two shaded portion (with the same Area)
Therefore, the area will be
The answer is
No, these do not always forma unique triangles because it depends on what size your sides are because if you have 3 sides of the same length then that’s a equilateral and if you have two sides of the same length and one side that’s not then that would be an Isosceles triangle and if you had no sides of the same length then that would be a scalene triangle.