Question

数学课上,老师告诉同学们,可以用已知半径的球去测量圆

Answer 1

不知对不对！！！

r= (5^2-((20-12)-5)^2)^0.5

= (25-(8-5)^2)^0.5

= (25-3^2)^0.5

= (25-9)^0.5

= (16)^0.5

= 4cm

d= 2*r=8cm

所以保温杯的内直径为：8厘米