What is the radius of a circle with the equation x^2+y^2+2x+4y- 9=0? Round your answer to the nearest thousandth.

Antonio made a scale model of a building. the model's scale is 1 inch to 235 feet and its height is 3.5 inches. what is the exact height of the actual building? enter your answer in the box.

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.

How many degrees are there in the central angles in a circle