3. Ko'paytuvchilarga ajrating: (5 ball) \[ x^{4}+5 x^{2}+9 \] 4. \( A B C \) uchburchakning \( B C \) tomoniga o'tkazilgan o'rta perpendikulyar \( A C \) tomonni \( D \) nuqtada kesib o'tadi. Agar \( B D=18,4 \mathrm{~cm}, A D=6,7 \mathrm{~cm} \) bo'lsa, \( A C \) kesma uzunligini toning. ( 5 ball)

Find the area of the sector of a at the centre is \( 140^{\circ} \). (Take \( \pi= \) Solution Area A of a sector is given by; \( \begin{aligned} \text { A }=\frac{\theta}{360} \times \pi r^{2}\end{aligned} \) \( \begin{aligned} \therefore \text { Area } & =\frac{140}{360} \times \frac{22}{7} \times 3^{2} \\ & =11 \mathrm{~cm}^{2}\end{aligned} \)

\( =11 \mathrm{~cm}^{2} \) Example 2 The area of a sector of a circle is 38.5 cm if the angle subtended at the centre is 90

5. \( A B C \) гурвалжны \( A B=B C=8 \) см ба талбай нь \( s=16 \mathrm{~cm}^{2} \) бол өнцөг \( A B C= \) ?

8. Uma regiāo triangular tem área igual a \( 16 \mathrm{~cm}^{2} \). Sabendo que a base é 4 cm , determine a altura dessa regiăo triangular.

A square prism measuring 2 m by 2 m in base length and 5 m in height has a half-sphere attached to the top. What is the total surface area of this composite solid?