9. An angle in a triangle is labeled as \( \angle A B C \). Explain why \( \overleftrightarrow{A B} \) and \( \overleftrightarrow{B C} \) can be used to define a plane. 10. a. In this figure, which trianclo:

SULrt \( 5 \quad \) Sebuah mesin memproses minuman mengeluarkan \( 62.92 \mathrm{~m}^{3} \) minuman schari daripada sebuah tangki. Tangki itu mempunyai jejari 2.2 m dan tinggi 4 m . Diberi bahawa isipadu tangki, \( V \) berubah secara langsung dengan kuasa dua jejari, \( j \mathrm{~m} \) dan tinggi, \( t \mathrm{~m} \). A beverage processing machine produces \( 62.92 \mathrm{~m}^{3} \) of beverage per day from a tank. The tank has a radius of 2.2 m and a height of 4 m. Given that the volume of the tank, \( V \) varies directly with the square of the radius, \( j \) mand the height, \( t \mathrm{~m} \). (a) Ungkapkan \( V \) dalam sebutan \( j \) dan \( t \). Express \( V \) in terms of \( j \) and \( t \).

a) Zeichne den Graphen folgender Funktionen in ein gemeinsemes Koordinatensysiem: (1) \( y=2 x+1 \) (2) \( -2 x-1 \) (3) \( y=2 x-1 \) b) Gib die Schnitpunkte der drei Geraden an.

b. La figura se armó con cubos cuyas aristas miden \( 3,5 \mathrm{~cm} \). Respuesta: ¿Cuál es el el volumen de la figura compuesta? de uno de los cubos?

\( 1^{\circ} \) a) Write \( \widehat{x O z} \) using \( \widehat{x O y} \) and b) Write \( \widehat{y O I} \) using \( \widehat{y O z} \) and c) Show that \( \widehat{x O z}=\widehat{y O t} \).

22. A rectangular foor of a room measures 5.4 m long and 4.2 m wide. The room is to be covere with square tiles. Calculate the minimum number of square tiles that can be used to cover the floor.