a)6-3=3 hours,means `1/4*360^0=90^0`
one right angled triangle
b)8-2=6 hours,means `1/2*360^0=1800^0`
two right angled triangle
c)11-5=3 hours,means `1/2*360^0=180^0`
two right angled triangle
d)13-10=3 hours,means `1/4*360^0=90^0`
one right angled triangle
e)9-0=9 hours,means `3/4*360^0=270^0`
three right angled triangle
f)12-6=6 hours,means `1/2*360^0=180^0`
two right angled triangle