As shown in the figure, De is the median line of △ ABC, M is the midpoint of De, and the extension line of CM intersects AB at point n, then s △ DMN: s quadrilateral anme equals () A. 1:5B. 1:4C. 2:5D. 2:7

As shown in the figure, De is the median line of △ ABC, M is the midpoint of De, and the extension line of CM intersects AB at point n, then s △ DMN: s quadrilateral anme equals () A. 1:5B. 1:4C. 2:5D. 2:7


∵ De is the median line of △ ABC, ∵ de ∥ BC, de = 12bc, if the area of △ ABC is 1, according to de ∥ BC, ∥ ade ∥ ABC, ∥ s ∥ ade = 14, am is connected. According to the title, s ∥ ADM = 12S ∥ ade = 18S ∥ ABC = 18, ∥ de ∥ BC, DM = 14bc, ∥ DN = 14bn, ∥ DN = 13bd = 13ad. ∥ s ∥ DNM = 13s ∥ ADM = 124, ∥ s quadrilateral anme = 14 − 124 = 524, ∥ s ∥ DMN: s quadrilateral anme = 124:524 = 1 So a



As shown in the figure, De is the median line of △ ABC, M is the midpoint of De, and the extension line of CM intersects AB at point n, then s △ DMN: s quadrilateral anme equals ()
A. 1:5B. 1:4C. 2:5D. 2:7


∫ De is the median line of △ ABC, ∥ de ∥ BC, de = 12bc. If the area of △ ABC is 1, according to de ∥ BC, ∥ s ∥ ade = 14, am is connected. According to the title, s ∥ ADM = 12S ∥ ade = 18S ∥ ABC = 18, ∥ de ∥ BC, DM = 14bc, ∥ DN = 14bn, ∥ DN = 13bd = 13ad. ∥ s



It is known that the three vertices of △ ABC are a (- 1,4), B (- 2, - 1), C (2,3). 1


First of all, the coordinate of point D is (0,1). Let the ad linear equation be y = KX + B. since it passes through two points a and D, B = 1, - K + B = 4 and K = - 3 are obtained, so the linear equation is y = - 3x + 1. As for the coordinate of D, it is the midpoint of BC, so its abscissa is (- 2 + 2) divided by 2 = 0, and its ordinate is (- 1 + 3) divided by 2 = 1



Given that the three vertices of △ ABC are a (- 5,0) B (3, - 3) C (0,2), try to find the point oblique equation of the line with the height on the edge of BC


The equation of the line BC is
(y+3)/(2+3)=(x-3)/(0-3)
That is y = - 5 / 3x + 2
So the slope of the high on the BC side is 3 / 5
Therefore, the point oblique equation is y = 3 / 5 (x + 5), that is, y = 3 / 5x + 3