Discovered attack 1

The discovered attack is one of the most important and common chess tricks. The trick can occur the moment you have two pieces on the same line (file, rank or diagonal). As soon as you move the piece in front, the piece behind (a rook, bishop or queen) can suddenly get free sight, allowing you to attack several enemy pieces at the same time.

What do you have to do? 

Win material by means of a discovered attack