Question

141 и 142, хотя бы один их них

Answer 1

$141.\;1)\;h^2+k^2=m^2\Rightarrow h=\sqrt{m^2-k^2}=\sqrt{(18,5)^2-(6)^2}=\\=\sqrt{342,25-36}=\sqrt{306,25}=17,5\;cm\\2\;)36+\left(\frac a2\right)^2=a^2\Rightarrow36+\frac{a^2}4=a^2\Rightarrow144+a^2=4a^2\Rightarrow3a^2=144\Rightarrow\\\Rightarrow a^2=48\Rihgarrow a=\sqrt{48}=\sqrt{16\cdot3}=4\sqrt3\\S_{CPD}=\frac12\cdot h\cdot a=\frac12\cdot18,5\cdot4\sqrt3=37\sqrt3\\3)\;S_{6OK}=6\cdot S_{CPD}\\S_{6OK}=6\cdot37\sqrt3=222\sqrt3$

$142.\;R=a\\1)\;\tan27^o57'=\frac hR\\h=R\cdot\tan27^o57'\\h=10\cdot0,5306=5,306\approx5,3\\2)\;b^2={R^2+h^2}\Rightarrow h=\sqrt{R^2+h^2}\\b^2=\sqrt{(10)^2+(5,3)^2}=\sqrt{100+28,09}=\sqrt{128,09}\approx11,3$