We know Sin theta is given by Perpendicular/ hypotenuse. Hence in this case the angle given is 30 degree and hypotenuse is given as 10 foot. Hence Sin 30= P/ 10 1/2= P/10 Hence on solving value of P is 5. Now we have to compute the theta value for Perpendicular as 5 and now the height of ramp is increased to 15 foot, hence hypotenuse is now 15 foot. Hence Sin theta= 5/15 On taking inverse of Sin Theta we will get the theta value as 19.47. Hence the angle of ramp should is 19.47 degrees.