A person standing on the bank of a river observes that the angle of elevation of the top of a tree standing on the opposite bank is $60^o$. When he moves 30 metres away from the bank, he finds the angle of elevation to be $30^o$. Find the height of the tree
AB and CD are two parallel chords of a circle whose centre is O and radius is 13 cm. If AB = 24 cm and CD = 10 cm, find the distance between AB and CD, if they lie on the same side of the centre O
Point M divides the line segment joining the points A (-1, 3) and B (9, 8) such that $AM \over BM$ = $k \over1$ . If M lies on the line x - y + 2 = 0, find the value of K