Well, from a theorical view, it's difficult to say...

The angle in bromine pentafluoride is 84.9: Bromine pentafluoride - Wikipedia, the free encyclopedia

Chlorine being bigger and having more electrons than fluorine I think would repel more and make a larger angle. But unless x-ray crystallography confirms this, I can't say for sure the bond angle.

Means we can say that approximately it has but not exactly?

That's what I would say, because unless we use the tools we have, we cannot just 'guess' the angle to be dead 90 degrees.