Question

Sum of external angles and internal angles of a polygon are equal.
(i)How many sides does that polygon have?
(ii)what is the sum of its internal angles?

Answer 1

hey mate..!!!
the answer is
i) 4 sides
ii) 360°

Answer 2

I can try.
let the internal angles be x1,x2,x3........xn
so external angles becomes 360-x1,360-x2,360-x3........360-xn.
ATQ:
x1+x2+......xn=360-x1+360-x2+.....360-xn
sigma(xn)=360n-sigma(xn)
sigma(xn)=180n
x1+x2+......xn=180n....

dont know after this.