How and where to hang pictures

[pinktransit]

I have 3 photographs, framed, with frame and mount they're about A3 size.
I want to put them up on the wall above my sofa, but have no idea of how best to arrange them. They are all landscape orientation.
I don't think that 3 in a row will work well, but neither will one above the other.
So diagonally? Randomly put wherever I happen to put a nail in?
They are of an elephant, a pair of hornbills and an agama lizard.

Is there a website or anything that makes suggestions? I used to have one big picture hanging there - I've never actually tried to make a group setting sort of thing before.
Suggestions please - otherwise I can see myself giving up, and just rehanging my original picture: this is a photograph of my 2 daughters, taken about 9 years ago. They won't be happy if I put it back up!

[Bonsoir]

Not randomly if they are a set (which it sounds as if they are). Horizontal sounds fine to me.

[pinktransit]

They are sort of a set, but not completely matching. Different scales, lighting, size - so one really close up, one less so, and one from more of a distance. They don't exactly match.
I think horizontal might work if I can get the spacing right. They are an awkward size, so to space them nicely they won't fit centrally over the sofa that's against that wall.

[OnePlanOnHouzz]

You might be better off adding another if you can find one ( ie one above the other twice ) if you have the wall space - ie from top of sofa to bottom of first pic (X )mm (300mm for pic ) then smaller gap of 150mm to bottom of next pic (300 for pic ) then (X) left to the ceiling ! Place them 75m to the left of centre and 75mm to the right of centre ( so middle gap is 150mm too ! ) to work out (X) take the height from top of sofa to ceiling - then subtract 300+300+ 150 = 750 and divide by two !

[OnePlanOnHouzz]

Alternatively look on here for tips www.sasinteriors.net/2011/07/creating-a-photo-wall-display/