AB=CD=x-7=25,4-7=18,4, MD=CD/2=18,4/2=9,2=Rcerc, Dcerc=9,2*2=18,4cm
calculam lungimea arcului de cerc=[tex] \pi [/tex]R=9,2[tex] \pi [/tex]in acest caz
P=AB+BC+CD+(AD-Dcerc)+larcului=18,4+25,4+18,4+7+9,2[tex] \pi [/tex]P=69,2+9,2[tex] \pi [/tex] ([tex] \pi [/tex]=3.14)
Afigurii=Adreptunghi-Asemicerc, Ad=Lxl=25,4x18,4=467,36, As=[tex] \pi [/tex][tex] R^{2} [/tex]/2=84.64[tex] \pi [/tex], Af=467,36+84,64[tex] \pi [/tex]