perhatikan gambar berikut! pada layang layang PQRS,PR = 25 cm,SQ=24 cm,dan RT = 16 cm. Maka berapakah keliling PQRS?

RS = 16^2 + 12^2
RS = 256 + 144
RS = √400 = 20

SP = 12^2 + 9^2
SP = 144 + 81
SP = √225 = 15

kll = 2 × (20+15)
kll = 70 cm^2

Ps = 15                         \
Sr = 20                            >   ( Teorema phytagoras)
Pq = 15                         /
Qr = 20                        /

Keliling = Ps + Sr + Pq + Qr = 15 + 20 + 15 + 20 = 70 cm