keliling bangun gabungan disamping adalah

Keliling trapesium= AB+BC+CD+DA
=40+32+28+32 cm
=132 cm

Keliling 1/2 lingkaran= 1/2 × phi × Diameter
= 1/2 × 22/7 × 28 cm
= 1/2 × 88 = 44 cm

Keliling trapesium - Keliling 1/2 lingkaran =
132-44 = 88 cm