I'm pretty sure that Garland drew an isosceles triangle. Because points A and C are an equal distance away from the vertex B. And the definition of an isosceles triangle is to have two sides that are equal in length.
the correct answer is a^6

The Area of Shaded region is equal to the difference in Area of rectangle and Area of triangle .
let's solve for area of rectangle :



Now, Area of Triangle :



So, the area of the shaded region in terms of x :


And since, Area of Shaded region = 44 cm²
By equating the area, we get

Value of x = 2

Answer:
I think the star just means a variable.