IR Sensors

How to connect two leged ir sensor and receiver to adruino.

Solder?

Not at all. Use "three legged".

but why not?

If you ask a sensible question, you will get a sensible answer too (hopefully :-)).

What problem are you trying to solve? What leads you to the conclusion that a "twolegger" (photo diode, photo transistor, photo resistor?) is the way to solve that problem?

joydey:
How to connect two leged ir sensor and receiver to adruino.

Here's how I use an led and diode, but that might not be what you have.

ir led and photodiode.PNG

ir led and photodiode.PNG