How many 1s are in 20?

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle

Geometry in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.

Which questions would most a reader identify the author's purpose for writing? check all that apply. what type of text is this? what type of reviews did the book receive? how many copies of the book have been sold? what is the central idea? how does this text make one feel?