A10 foot ladder must make an angle of 30 with the ground if it is to reach a certain window. what angle must a 20 foot ladder make with the ground to reach the same window? a. 10.5 degree b. 12.5 degree c. 14.5 degree d. 16.5 degree

See the attached figure to better understand the problem

we know that

in the triangle ABC
sin 30=AB/10------> AB=10*sin 30-----> AB=10*(1/2)----> 5 ft

in the triangle ABD
sin D=AB/20--------> sin D=5/20----> sin D=0.25
D=arc sin(0.25)-----> D=14.48°------> D=14.5°

the answer is the option
c. 14.5 degree