Can the locus of the points idea can be used to define straight lines, cicles, and even more complex shapes such as parables

Alex drew a circle with right triangle prq inscribed in it, as shown below: the figure shows a circle with points p, q, and r on it forming an inscribed triangle. side pq is a chord through the center and angle r is a right angle. arc qr measures 80 degrees.

The border line of the linear inequality 4x + 7y < 5 is dotted true or false?

The vertex of this parabola is at (-2,-3). when the x-value is -1, the y-value is -5. what is the coefficient of the squared expression in the parabola's equation?