Zoe is using the figure shown below to prove pythagorean theorem using triangle similarity.

in the given triangle abc, angle a is 90o and segment ad is perpendicular to segment bc.

which of these could be a step to prove that bc2= ab2 + ac2?

a.) triangle adc is similar to triangle adb by the aa similarity theorem.
b.) triangle abc is similar to triangle dba by the aa similarity theorem.
c.) triangle abc is similar to triangle dba by the sas similarity theorem.
d.) triangle adc is similar to triangle adb by the sas similarity theorem.