1 7 x 21 4 July 8, 2019 16 32 64 128 1 7x 21 =- 4 1 4 x 22 7 x 21 21 x 7 1/2 1/2 x 7 x4 7 1/2 x 4 1 4 x 7 7 1/2 x 4 1/2