Answer:
160 cm²
Step-by-step explanation:
V = 1/3 * 24 * 20 = 160 cm²
Stir salt and water in a saucepan over heat 4-5 minutes.
Remove from heat; add cornstarch and cold water.
Stir until smooth; return to heat and cook until thick.
Allow the clay to cool, then shape as desired.
When dry, decorate with paint, markers, glitter, and so on.