How many seconds will it take an echo to reach your ears if you yell toward a mountain 82 m away on a day when the air temperature is 0º C? time =?

The point of intersection of the diagonals of a rectangle is 4 cm further away from the smaller side then from the larger side of the rectangle. the perimeter of the rectangle is equal to 56 cm. find the lengths of the sides of the rectangle. 16 points answer quick