ducem CE inaltimea pe AB
triunghiul ABC dreptunghic
AB=√[6²+(2√7)²]=√(36+28)=√64=8
notam EB=x si AE=8-x
teorema inaltimii
CE²=6²-x²=36-x²
CE²=(2√7)²-(8-x)²=28-64+16x-x²=-36+16x-x²
36=-36+16x
16x=72
x=4,5 cm
CE=√(6²-4,5²)=√15,75=1,5√7≈3,97 cm
DC=AE=8-4,5=3,5
Atrapez=(3,5+8)×1,5√7/2=11,5×1,5√7/2=8,625√7≈22,82 cm²
