Question

Vaaaaaaa roggg repede!!!! Problema partea 3

Answer 1

Răspuns:

Explicație pas cu pas:

a)

A=(AB+CD)×AD/2=(100+60)×20√3/2=160×10√3=1600√3

A=1600√3m²

b)

Aria ΔBCE=Atr.

Stim ca Atr=A/2

Cum perpendiculara din C pe BE (s-o notam cu CM) este egala cu AD, CM=AD obtinem ca  Atr=BE×CM/2=BE×AD/2

Deci BE×AD/2=A/2⇒BE×AD=A ⇒BE=A/AD

BE=1600√3/20√3=80.

BE=80m

Observam ca BM=AB-CD=100-60=40

BM=40m.

Atunci EM=BE-BM=80-40=40m.

In ΔCEM dreptunghic in M,

CE²=CM²+EM²=(20√3)²+40²=1200+1600=2800

CE²=28×100=4×7×100

CE=20√7

c)

Aria ΔABD=Atr1=AB×AD/2=100×20√3/2=2000√3/2=1000√3

Aria ΔDCB=Atr2=A-Atr1=1600√3-1000√3=600√3

Atr2=600√3m²

A.............100%

Atr2............x%

x%=Atr2×100/A

x%=600√3×100/1600√3=600/16=75/2=37,5

x%=37,5%