An astronaut on the moon throws a baseball upward. The astronaut is 6 ft 6 in tall, and the initial velocity of the ball is 40 ft per sec. The heights of the ball in feet is given by the equation S = -2.7t^2+40t+6.5, where t is the number of seconds after the ball was thrown.
After how many seconds is the ball 18 ft above the moon's surface?

The percent increase is 25%

The sum of the angles in a triangle is 180°. this is called the angle-sum property.the sum of the lengths of any two sides of a triangle is greater than the length of the third side. similarly, the difference between the lengths of any two sides of a triangle is less than the length of the third side.the side opposite to the largest angle is the longest side of the triangle and the side opposite to the smallest angle is the shortest side of the triangle.