The length of AD (in cm.) is
A convex lens is in contact with concave lens. The magnitude of the ratio of their focal length is (2/3). Their equivalent focal length is 30 cm. What are their individual focal lengths (in cm)?
The cross-section of a trough of depth 36 cm is a trapezium ABCD where AB = 50 cm as shown. If the area of ABCD is 2250 cm2, find the length of CD in cm.
The altitude AD of in ΔABC is 10 cm. The ∠A is an obtuse angle and BD = 10 cm, CD = 10√3 cm. Find ∠A.