Question

Помогите с геометрией 8 класс

Answer 1

Ответ:

Объяснение:

$1) S = frac{1}{2} ab*sinalpha = frac{1}{2} *4*6*frac{sqrt{2} }{2} = 6sqrt{2}\2) S = sqrt{p(p-a)(p-b)(p-c)} , p = frac{a+b+c}{2} = frac{13+14+15}{2} = 21\ S = sqrt{21(21-13)(21-14)(21-15)} = sqrt{21*8*7*6} =sqrt{7056} =84\3) frac{8}{sin90} = frac{x}{sin30} \8 = frac{x}{0,5} ; x = 4\y = sqrt{64 - 16} = sqrt{48} = 4sqrt{3} \S = frac{1}{2} *x*y = frac{1}{2} *4 *4sqrt{3} = 8sqrt{3}$$4) Osnovanie- treugolnika = x:\ frac{x}{2} = sqrt{25-16} = sqrt{9} = 3 \x = 6\\S = frac{1}{2} * h * x = frac{1}{2} * 4 * 6 = 12\5) - ?\6) S = a* h = 5 * 8 = 40\7) S = a * b * sinalpha = 6 * 6 * frac{sqrt{2} }{2} = 18sqrt{2} \8) S = hfrac{a + b}{2} = 2 * frac{3 + 4}{2} = 7\9) - ?\10) S = MN * BH = 7 * 3 = 21$