A semicircular protractor has a diameter of 14 cm. What is its perimeter in cm? (Use π = 22/7.)

The boundary is the semicircular arc plus the straight edge along the diameter: π$r+d=(22/7)\times 7+14=22+14=36$ cm. The trap 22 is the arc alone, with the straight edge left out — a semicircle's boundary is not merely half a circumference; 44 is the full circle's circumference; 58 adds the diameter to that full circumference.