Question

ПОМОГИТЕ ДАЮ 100 БАЛЛОВ

Answer 1

$R=\frac{a^{2} }{\sqrt{4a^{2}-b^{2} } }=\frac{81}{4*81-9*11}=\frac{81}{\sqrt{324-99} }=\frac{81}{\sqrt{225} }=\frac{81}{15}=5.4\\ D=2R=2*5.4=10.8$

10.8