B) Sovent \( A, B \). Cet \( D \) quarre points du plan ou de respace meni d un repere orthonormé. Calcules \( \overrightarrow{A B} \cdot \overrightarrow{C D} \) s: \( \begin{array}{ll}\text { 1) } \overrightarrow{A B}\binom{-5}{1} \text { et } \overrightarrow{C D}\binom{-3}{2} & \text { 2) } A(3 ; 4), B(-2 ; 1), C(4 ;-2) \text { et } D(-1 ;-3) \\ \text { 3) } \overrightarrow{A B}\left(\begin{array}{c}4 \\ 1 \\ -2\end{array}\right) \text { et } \overrightarrow{C D}\left(\begin{array}{c}-3 \\ -1 \\ 2\end{array}\right) & \text { 4) } A(3 ; 0 ; 4), B(-2 ; 1 ; 1), C(4 ;-2 ;-3) \text { et } D(-1:-3 ; 2)\end{array} \)

Determine the equation of a circle with centre \( (0 ; 0) \) and a point \( (3 ; 4) \) on the perimeter of the cirlce. (A) \( x^{2}+y^{2}=16 \) (B) None of these (C) \( x^{2}+y^{2}=12 \) (D) \( x^{2}+y^{2}=9 \) (E) \( x^{2}+y^{2}=25 \)

A cuboid has a total surface area of \( 94 \mathrm{~cm}^{2} \). If its length is 5 cm and breadth is 3 cm , find its height.

The geometrical centre of square ABCD is the origin and its side length is \( 2 \sqrt{3} \) , then the equation of the circle that touches its sides is \( \begin{array}{ll}\text { (a) } x^{2}+y^{2}=3 & \text { (b) } x^{2}+y^{2}=12 \\ \text { (c) } x^{2}+y^{2}=6 & \text { (d) }(x-\sqrt{3})^{2}+(y-\sqrt{3})^{2}=3\end{array} \)

The edge of a cube is doubled. By what factor will its surface area and volume increase?

The graph of \( 4 x+7 y=0 \) is a lime passing through origin. True.