Question

ae giúp mình với

Answer 1

a: S ABED=1/2*15*20=150cm²

b: AD^2+AB^2=225

AD^2+DC^2+CE^2+2*DC*CE=400

=>CE^2+2*DC*CE=175

=>CD^2=175/8

=>CD=5/4*căn 14(cm)

=>CE=5/2*căn 14(cm)

=>DE=15/4*căn 14(cm)

AD^2=AE^2-DE^2

=>AD=5*căn 130/4(cm)

=>BC=5/4*căn 130(cm)

S BCD=1/2*BC*CD=1/2*5/4*căn 130*5/4*căn 14=25/32*căn 1820(cm²)

=>S BCE=25/16*căn 1820(cm²)