Answer:
Not isosceles
Explanation:
The given, is a right triangle because AC is perpendicular to BC so x = 30
For the triangle to be isosceles |AC| must be equal to |BC|
x + 20 ➡ 30 + 30 = 50
2x - 20 ➡ 60 - 20 = 40 as we can see the length of sides aren't equal so the triangle is not isosceles.