Răspuns:
Explicație pas cu pas:
construim CE⊥AB si DF⊥ AB
ΔCEB = drept.
CE²=BE*AB
6²=BE*10
BE =36/10 =3.6 cm⇒ AF=BE =3.6 cm .
⇒CD=AB-AF-BE
CD=10-3.6-3.6 =2.8 cm (FE=CD=2.8 cm)
AE =AF+FE
AE =3.6+2.8=6.4 cm
CE²=BC²-BE²
CE²=6²-3.6²=36-12.96
CE²=23.04
CE=√23.04=4.8 cm
Aabcd=(10+2.8)*4.8/2 =30.72 cm²
Aabc =10*4.8/2 =24
b)
30.72 ----------100%
24 ---------------x
x=24*100/30.72 =78.125 %
