Question

六年级暑假新时空数学，全部答案

Answer 1

英语:1ccabb dadba dcaac bccbc abada 数学:A+C=2B, ==> B=60, log4sinA+log4sinC=-1 ==> sinAsinC = 1/4 面积 = 根号3 = a*b*sinC/2 ...(1) 面积 = 根号3 = b*c*sinA/2 ...(2) 面积 = 根号3 = c*a*sinB/2 = c*a*[(根号3)/2]/2...(3) (3): ==> c*a = 4 ...(4) (1)*(2): 12 = a*b^2*c*(sinAsinC) = a*b^2*c*(1/4) = b^2 ==> b=2*根号3 b^2 = a^2 + c^2 - 2ac*cosB ===> a^2 + c^2 = 16 ...(5) (4)(5): a = 根号6 + 根号2, c = 根号6 - 根号2 因此：三条边长分别为：a = 根号6 + 根号2；b=2*根号3；c = 根号6 - 根号2。