B. 12 cm
C. 13 cm
D. 14 cm
In the figure, D is a point lying on AC such that BD is perpendicular to AC. It is given that AD = 8 cm and DC = 18 cm . Find the length of BD.
呢種題型係經常都考 , 我地會用90o– x , x 同90o去證明兩個三角形Similar
而且因為題目只提供兩條邊 , 所以選擇邊一對Similar Triangle(圖中有3對)係要考慮兩個三角形都同時有BD呢一條邊
In the figure, O is the center of the circle and AOC is a straight line. If AB and BC are tangents to the circle such that AB = 3 and BC=4, then the radius of the circle is