夹角=30°+30°+90°=150°.
两边长:24*2=48,20*2=40
另一边x
cos150°=(48^2+40^2-x^2)/(2*48*40)=-[3^(1/2)]/2
2304+1600-x^2=1920*3^(1/2)
x^2=48^2+40^2-1920*3^(1/2)=64[36+25+30*3^(1/2)]
x=8*[61+30*3^(1/2)]^(1/2)
夹角=30°+30°+90°=150°.
两边长:24*2=48,20*2=40
另一边x
cos150°=(48^2+40^2-x^2)/(2*48*40)=-[3^(1/2)]/2
2304+1600-x^2=1920*3^(1/2)
x^2=48^2+40^2-1920*3^(1/2)=64[36+25+30*3^(1/2)]
x=8*[61+30*3^(1/2)]^(1/2)