Answer: 10 verticesTo make a full circle(360 °), the number of 40° lines you need will be: 360/40=9 lines. So, the base of the pyramid would be made of 9 lines.Pyramid has a base and sides. The sides number is equal to the number of lines of the base. Then, the number of faces/vertices would be: 1 + 9= 10
If the question saying literally 40 edges(not degrees), then the pyramid base would be 40 lines. In this case, the number of vertices would be: 1+40=41
That decimal is equivalent to
45,833,333,333 / 100,000,000,000 .
If the numerator and denominator have any common factor,
then the fraction can be simplified. But I doubt it.
Axis of symmetry is the x value of the vertex
the x value of the vertex, in form
y=ax^2+bx+c is -b/(2a)
so
y=-5x^2-10x-15
a=-5
b=-10
x value of vertex is -(-10)/(2*-5)=10/-10=-1
x=-1 is axis of symmetry