Why does a pin support only have reactions towards the pin?

[goldfish9776]

Homework Statement

why the reaction of pin is only acted towards the pin ( the horizontal of reaction of the force is directed to the left , whereas the the vertical component is acted upwards ) , why can't the horizontal of reaction of the force is directed to the right , whereas the the vertical component is acted downwards ? since the pin support will resists all translation , right ?

Homework Equations

The Attempt at a Solution

 

[SteamKing]

Homework Statement

why the reaction of pin is only acted towards the pin ( the horizontal of reaction of the force is directed to the left , whereas the the vertical component is acted upwards ) , why can't the horizontal of reaction of the force is directed to the right , whereas the the vertical component is acted downwards ? since the pin support will resists all translation , right ?

Homework Equations

The Attempt at a Solution

You're taking this diagram too literally.

The point is, a pin connection can take a reaction which has both vertical and horizontal components. The direction in which the arrows point in this diagram is irrelevant.

The simple support shown just above the pinned support seems to be in error. Simple supports can take only vertical reactions, not horizontal reactions.