3•85+90=345
Рада была вам помочь..
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](https://tex.z-dn.net/?f=S_%7BOCH%7D%3D%5Csqrt%7Bp%28p-a%29%28p-b%29%28p-c%29%7D%5C%5Cp%3D%2813%2B14%2B15%29%3A2%3D42%3A2%3D21%5C%5Ca%3D13%2C%5C%3Bb%3D14%2C%5C%3Bc%3D15%5C%5CS_%7BOCH%7D%3D%5Csqrt%7B21%2821-13%29%2821-14%29%2821-15%29%7D%3D%5Csqrt%7B21%5Ccdot8%5Ccdot7%5Ccdot6%7D%3D%5Csqrt%7B7056%7D%3D84%5C%5C%5C%5C42x%2B2%5Ccdot84%3D378%5C%5C42x%2B168%3D378%5C%5C42x%3D210%5C%5Cx%3DAA%27%3D5)
-30-29-28-27-26-25-24-23-22-21-20-19-18-17-16-15-14-13-12-11-10-9-8-7-6-5-4-3-2-1+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27=
-30-29-28 (остальное сократится)= -59-28= -87