Answer:
refer to the phôt
the length of 1 side is 14 cm
Explanation:
obtuse triangle -> angle A > 90
isosceles triangle -> a = b
if A = 90 then a1^2 + b1^2 = c^2 (a1,b1 is the length when A=90)
a1^2 + a1^2 = c^2
2 * a1^2 = 20^2 = 400
a1 ^2 = 200
a1 = 14.14cm
if A>90 -> a < a1
as a is greatest whole number possible, a = 14 cm