Help me in finding the angle

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Which of the following is an example of a rational number? a. π b. √ 9 c. √ 8 d. 3.8362319

Answer this two poles, ab and ed, are fixed to the ground with the of ropes ac and ec, as shown: two right triangles abc and edc have a common vertex c. angle abc and edc are right angles. ab is labeled 13 feet, ac is labeled 15 feet, ec is labeled 10 feet, and ed is labeled 4 feet. what is the approximate distance, in feet, between the two poles? 11.14 feet16.65 feet14.35 feet15.59 feet