You didn't give your choices but sin 21 equals 0.358.
This type of erosion is primarily by movement of particles that make<span> up the bed load. </span>Stream Deposition<span>. A </span>stream<span> is at its base level where </span>it<span> meets a large body of water. As a </span>stream gets<span> closer </span>to<span> the base level, its gradient lowers. </span>