Rectangular 25 18 20 (2620)
Surface area = 2 (25 *18+25 * 20+18 * 20) = 2620.
16 10 (8 ) 736
(736-2* 16* 10)÷2÷( 16+ 10)=8
Square141414 (1176)
14* 14*6= 1 176