Direction: Consider the following for the items that follow:

A triangle ABC is inscribed in the circle x² + y² = 100. B and C have coordinates (6, 8) and (-8, 6) respectively.

What are the coordinates of A? 

Direction: Consider the following for the items that follow:

ABCD is an isosceles trapezium and AB is parallel to DC. Let A(2, 3), B(4, 3), C(5, 1) be the vertices.

What are the coordinates of vertex D?

Direction: Consider the following for the items that follow:

ABCD is an isosceles trapezium and AB is parallel to DC. Let A(2, 3), B(4, 3), C(5, 1) be the vertices.

What is the point of intersection of the diagonals of the trapezium?

Direction: Consider the following for the items that follow:

Let 2x² + 2y² + 2z² + 3x + 3y + 3z - 6 = 0 be a sphere.

What is the diameter of the sphere?