[填空题]
The diagram below shows the triangle t fhjpx0kg c452q-0 hg3hc;uqABC. The point C has coo 7g9k m2t2goozrdinates (9,5) and the equation of the line (AB) i o7z2m 29oktggs 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 ≈