[填空题]
The side lengths of a quadril4ywxzq6c5q z:ateral ABCD are A)rq)x.d aikl) B =6 mm, BC =5 mm, CD =8 mm, and DA = 9 mm. The angle r)aq il)dxk.)$\mathrm{A}\hat{\mathrm{B}}\mathrm{C}$ is equal to $90^{\circ}$.
1.Calculate the length of AC. mm
2.Calculate the size of angle $\mathrm{A}\hat{\mathrm{D}}\mathrm{C}$. $^{\circ}$
3.Calculate the area of triangle ACD. $mm^2$
4.Calculate the area of quadrilateral ABCD. $mm^2$
A point P is chosen on the side CD in a such a way that the area of triangle ACP is equal to the area of the triangle ABC.
5.Calculate the length of CP. mm
6.Calculate the length of AP. mm