Solution:
We have to find the number of sides when each angle of a polygon isWe know that measure of each interior angle of a regular polygon with n sides is given as,
= ×
Substitute 90∘ for θ and solve the equation to determine the value of n,
= ×
=
Cross-multiply and rearrange the above equation,
2(n - 2) = n
2n - 4 = n
n = 4
Hence, the number of sides is 4.