1. Construct the following right- angled triangle ABC using a ruler and a pair of compasses \( \mathrm{AB}=7 \mathrm{~cm} \), angle \( \mathrm{BAC}=90^{\circ}, \mathrm{AC}=6 \mathrm{~cm} \) (2marks)

Câu 20. Cho hình chóp \( S, A B C D \) có đáy \( A B C D \) là hình bình hành. Gọi \( G, K \) lần lượt là trọng tâm các tam giac \( S A D, S C D \) a) Tìm giao tuyyên \( (S A D) \) và \( (S B C) \). b) Chứng minh rằng: \( G K / /(A B C D) \).

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

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.

If the straight line \( y=m x \) touches the circle \( (x-2)^{2}+(y-6)^{2}=4 \), then \( m=\ldots \ldots \) \( \begin{array}{llll}\text { (a) } \frac{1}{3} & \text { (b) } \frac{2}{3} & \text { (c) } \frac{-4}{3} & \text { (d) } \frac{4}{3}\end{array} \)

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 \( \begin{array}{ll}\text { (a) } x^{2}+y^{2}=3 & \text { (b) } x^{2}+y^{2}=12 \\ \text { (c) } x^{2}+y^{2}=6 & \text { (d) }(x-\sqrt{3})^{2}+(y-\sqrt{3})^{2}=3\end{array} \)