Jawabanmu

2014-06-12T09:34:24+07:00
L. Permukaan = 2. L alas + 4. L slimut = 2. (21. 21) + 4. (10. 21) = 2. 441 + 4. 210 = 882 + 840 = 1722 cm kuadrat.

bener gak yah ?
2014-06-12T12:34:10+07:00
2.luas alas + keliling × tp
2.21×21 + (21+21) × 10
2.441 + 42×10
882 + 420
...... cm