Personalized Pi Day Party Funny Math Long Sleeve T-Shirt. Funny math design has Pi Day symbol in a slice of pie on this humorous math lover Long Sleeve T-Shirt - Red. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL