[填空题]
The diagram below shows the triangle ABC.m8ck1x *tn n/2a/wt hhdms,2 g Thlvog*o2- bf5m*sfhy nn 7 q.4ge point C has coordinates (9,5) and the equation of the mg.n g2 sh*n5fobv q7-4loyf*line (AB) is x+4y=12.
1.Find the coordinates of:
(1)A; y =
(2)B. x =
2.Show that the length of [AB] is 12.412.4 correct to three significant figures. AB ≈
The point D lies on the line (AB). The line (CD) is perpendicular to the line (AB).
3.Find:
(1)the gradient of (CD); $m_{CD}$ =
(2)the equation of (CD). y =ax+b a = b =
4.Find the coordinates of D. (a,b) a= b=
5.Calculate the length of [CD] correct to three significant figures. CD ≈
6.Calculate the area of triangle ABC. A ≈