Question

the diagonals AC and BD of a parallelogram intersect at the point O, if AD is equal to 6.8 cm and BD is equal to 13.6 find the value of DC

Answer 1

we have given, AD=6.8cm
BD=13.6cm

now we now this is parallelogram so, AD=BC
AB=DC
So, BC=AD
BC=6.8cm
now we have ,BC=6.8cm
BD=13.6cm
so with Pythagoras theorem

H^2 = B^2 + P^2
BD^2 = DC^2 + BC^2
13.6^2 = DC^2 + 6.8^2
184.95 = DC^2 + 46.23
DC^2 = 184.95 - 46.23
DC^2 = 138.72
DC = root 138.72
DC = 11.78cm