Question

Стереометрия 1,3 очень надо

Answer 1

1.

Sбок = 5*6*2+4*6*2 = 60+48 = 108 ед²

Sполн = Sбок+2Sосн = 108+2*5*4 = 108+40 = 148 ед²

3.

AA' = x

Sполн = 13x+14x+15x+2Sосн = 42x+2Sосн

$S_{OCH}=\sqrt{p(p-a)(p-b)(p-c)}\\p=(13+14+15):2=42:2=21\\a=13,\;b=14,\;c=15\\S_{OCH}=\sqrt{21(21-13)(21-14)(21-15)}=\sqrt{21\cdot8\cdot7\cdot6}=\sqrt{7056}=84\\\\42x+2\cdot84=378\\42x+168=378\\42x=210\\x=AA'=5$