Begin by painting or coloring your plate blue. If you're wanting this to be a faster craft you can use markers, crayons or colored pencils. You could also pre-paint plates too and have them ready for the kid to pick from.
Allow the plate to fully dry, then flip it over and use it as an outline to create a half circle on the white construction paper.
Cut out a red mouth and white teeth pieces. Also cut out three triangular pieces to be the fins. You can make these as big or small as you want! You could have these pre-cut and sitting out for kids to pick from too.
Glue on the eyes, fins, mouth and teeth. If you don't have googley eyes handy or available you can use white paper to make cut out eyeballs and color the pupils black. You can customize your shark with different fins, teeth sizes, an angry face vs. a happy one...seeing what kids come up with is the best part!