I mark as brainliest

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

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?

Line segment eg is partitioned by point f in the ratio 1: 1. point e is at e (0, 4), and point f is at (1, 3). what are the coordinates of point g? (−1, 5) (2, 2) (3, 1) (4, 0)