\( \begin{array}{llll}\text { In a quadrilateral, all the sides are equal, but diagonals are not equal, it is called } \\ \text { a) Rectangle } & \text { b) Rhombus } & \text { c) Trapezium } & \text { d) Square }\end{array} \) \( \begin{array}{llll}\text { a) }(-8) & \text { b) } 8 & \text { c) } 2 & \text { d) (-2) }\end{array} \)

एक गोलाकार काँच के बर्तन की एक बेलन के आकार की गर्यन है, जिसकी सम्बाई 7 सेमी तया व्यास 2 सेमी है, जबकि गोलाकार भाग का व्यास 8.4 सेमी है। छ्रात कीजिए कि बर्तन में कितना पानी भरा जा सकता है?

Arc Length Find the arc length for the following. 13. A circle has a radius of 5.75 inches. Find the length of the arc intercepted by a central angle of \( \frac{5 \pi}{6} \). 14. A circle has a diameter of 10 inches. Find the length of the arc intercepted by a central angle of \( 125^{\circ} \).

در یک مثلث 45°-45°-90°, اگر طول یکی از اضلاع برابر با 8 واحد باشد، طول وتر را محاسبه کنید.

यदि त्रिभुज ABC समबाहु त्रिभुज भएको अवस्थामा \( \Varangle \mathrm{ABC} \) र शीर्षबिन्दु A तथा बिन्दु D लाई \( \mathrm{AC}=\mathrm{CD} \) हुद शत जोड्दा बन्ने \( \triangle \mathrm{ACD} \) मा बनेको कोण \( \Varangle \mathrm{CAD} \) बिचको अनुपात गणना गरी उल्लेख्य गर्नुहोस् । If triangle \( A B C \) is an equilateral triangle then calculate and mention the ratio between \( \angle A B C \) and \( \angle C A D \) formed in \( \Varangle A C D \) which is formed by joining vertex \( A \) and point \( D \) in such a way that: \( A C=C D \).

Bài 3. Cho \( D A B C \) có \( \mathrm{AB}<\mathrm{AC} \). Trên tia BA lấy điểm D sao cho \( \mathrm{BD}=\mathrm{BC} \). Nối C với D . Tia phân giác góc B că̆t cạnh \( \mathrm{AC}, \mathrm{DC} \) lần lượt tại E và I . \( \begin{array}{ll}\text { a) Chứng minh } \triangle \mathrm{BED}=\triangle \mathrm{BEC} \text {. } & \text { b) Chứng minh } \mathrm{IC}=\mathrm{ID} \text {. } \\ \text { c) Từ } A \text { vẽ đường thẳng } \mathrm{AH} \text { vuông góc với } \mathrm{DC}(\mathrm{H} \text { thuộc } \\ D C) \text {. Chứng minh } \mathrm{AH} / / \mathrm{BI} \text {. } & \end{array} l \)