Find the number of sides in a polygon if the sum of its interior angles is :
(i) 900o
(ii) 1620o
(iii) 16 right - angles
(iv) right - angles.
(i) Let no. of sides = n
Sum of angles of polygon = 900o
∴ (n−2)×180o=900on−2=900180n−2=5n=5+2n=7.
(ii) Let no. of sides = n
Sum of angles of polygon =1620o
∴(n−2)×(180o)=1620on−2=1620180n−2=9n=9+2n=11.
(iii) Let no. of sides = n
Sum of angles of polygon = 16 right angles
=16×90=1440o∴(n−2)×180o=1440on−2=1440180n−2=8n=8+2n=10.
(iv) Let no. of sides = n
Sum of angles of polygon = 32 right angles
=32×90=2880o∴(n−2)×180o=2880n−2=2880180n−2=16n=16+2n=18.