1) х+х+3х+3х=40. 8х=40. х=5дм. -1 сторона. 5 *3 = 15дм. -2 см.
R=1/2d =1.5cm
1)<span>.найти объем шара</span>
<span>V=4/3 <span>π R^3 V=4/3<span>π*1.5^3=4.5<span>π (cm^3)</span></span></span></span>
<span><span><span><span>2) <span>площадь сферы</span></span></span></span></span>
<span><span><span><span><span>S= 4 <span>π R^2 S=4 <span>π*1.5^2=9<span>π (cm^2)</span></span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span>3) <span>площадь кругa</span></span></span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span><span>Sкр=<span>π R^2 S=2.25<span>π (cm^2)</span></span></span></span></span></span></span></span></span></span></span>
<span>1) найдём координаты т.А(x;y;z),используя вектор СА:
{x-5=-3
{y-8=4
{z-0=2
A(2;12;2)
2) ABCD-пар-м⇒вектор CB=вектору DA⇒DA(5;-2;4)
3) найдём координаты т.D(x;y;z)
{2-x=5
{12-y=-2
{2-z=4
D(-3;14;-2)
4) -3+14+(-2)=9</span>