Here's why:

* Central Carbon: The carbon atom in methane is at the center.

* Four Hydrogen Atoms: Four hydrogen atoms are bonded to the carbon atom.

* Bond Angles: The bonds between the carbon and each hydrogen atom are spaced out as evenly as possible, creating an angle of approximately 109.5 degrees.

* Shape: This arrangement of four bonds around a central atom results in a three-dimensional shape resembling a pyramid with a triangular base, which is known as a tetrahedron.