Three questions in primary school [...] = = ~ Thank you for your answers about the circle. A reward of 30 pounds.
(1)1.8× 3.14× 450× 60 =152604 (m) = 152.604 (km)
(2) 15.7×4÷3. 14=20 (cm)
(3)37.68÷3. 14÷2=6 (m)
6+ 1=7 (m)
7× 7× 3.14-6× 6× 3.14 = 40.82 (square meter)