Question

Circumference of a semi circle whose diameter is 2.8cm

Answer 1

radius = diameter/2
radius = 2.8/2
radius = 1.4cm
circumference of circle = 22/7 × 1.4
circumference of circle = 4.4cm

Answer 2

diameter =2.8
radius=2.8/2=1.4
circumference =π+2 r units
π=22/7+2x1.4=7.2