R^2+4r+3 completing the square

What are the soultion(s) to the quadratic equation 40- x^2=0

Asailor is looking at a kite. if he is looking at the kite at an angle of elevation of 36and the distance from the boat to the point where the kite is directly overhead is 40 feet, how high is the kite?

72 the length of a side of a triangle is 36. a line parallel to that side divides the triangle into two parts of equal area. find the length of the segment determined by the points of intersection between the line and the other two sides of the triangle.