The correct option is A 1
In △ABC, AD⊥BC AB=13, BD=5, DC=16
Now, In △ABD,
AB2=AD2+BD2
132=AD2+52
AD2=144
AD=12
Now, in △ADC,
AC2=AD2+CD2
AC2=122+162
AC2=144+256
AC=20 cm
Now, sin2C+cos2C=(PH)2+(BH)2=(ADAC)2+(BDAC)2
= (1220)2+(1620)2
= 144400+25625
= 400400
= 1