Answer:
if you use the 10 feet ladder base is 6 feet
if you use 12 feet ladder base is 8.94 feet
if you use 15 feet ladder base is 12.69 feet
Explanation:
you know the ladder length so you know the hypotenuse
you can use a^2 + b^2= c^2
for example you use the 10 feet ladder
8^2+b^2 = 10^2
64 + b^2 = 100
subtract 64 from both sides
b^2=36
to get rid of the exponent find square root
b= 6
you can plug in the different values like 15 or 12