Answer:
By comparing the ratios of sides in similar triangles ΔABC and ΔADB,we can say that 
Step-by-step explanation:
Given that ∠ABC=∠ADC, AD=p and DC=q.
Let us take compare Δ ABC and Δ ADB in the attached file , ∠A is common in both triangles
and given ∠ABC=∠ADB=90°
Hence using AA postulate, ΔABC ≈ ΔADB.
Now we will equate respective side ratios in both triangles.

Since we don't know BD , BC let us take first equality and plugin the variables given in respective sides.

Cross multiply

Hence proved.
Answer:
Step-by-step expla2nation:
AC = √(40²-12²) = √(1600-144) = √1456 = 4√91
tanA = 12/4√91 = 3/√91 = 3√91/91
option а.
Answer:
they are
Step-by-step explanation:
the simplest form 8/18 is 4/9