Answer:
solution :
in the given figure AB=10.2cm, AC=14cm, AD=DC and AD perpendicular to BC.
now ,
in rt angle tirangle ADC,
angleACD=45 degree, angle DAC=45 degree now,
in triangle ABD,
angle BAD+angleABD+angleADB=180 DEGREE (sum of the sngle of triangle)
angle BAD+75+30=180
angle BAD=180-165 therefore,angle BAD=15
angle BAC =15+45=60
Area of triangle ABC=1/2×AB×AC×SIN 60
=1/2×10.2×14×√3/2
=61.83cm³ ans
