No, Orion's Belt is not part of the Big Dipper. Orion's Belt and the Big Dipper are two distinct and separate asterisms in the night sky.
Orion's Belt is a prominent feature of the constellation Orion. It consists of three bright stars in a straight line, named Alnitak, Alnilam, and Mintaka. These stars are often referred to as Orion's Belt due to their alignment.
On the other hand, the Big Dipper is a well-known asterism in the constellation Ursa Major, also known as the Great Bear or the Plough. It is formed by seven bright stars that resemble a ladle or dipper shape. The Big Dipper is a recognizable feature of the northern sky and is used as a navigational tool to locate the North Star (Polaris).
While both Orion's Belt and the Big Dipper are visible in the night sky, they are located in different constellations and have distinct shapes and arrangements of stars.