O is the centre of a circle and AB is the tangent to it touching at B . If OB = 3 cm. and OA = 5 cm , then the measure of AB in cm

In a ∆ABC, BC is extended upto D, ∡ACD =120°, ∡B = 1/2 A. Then ∡A is

If x = 3+13, then the value of x-12642x-1x-233 is

If √x ­- √y = 1 , √x + √y = 17 then √xy = ?

The average of 100 observations was calculated as 35.It was found later, that one of the observation was misread as 83 instead of 53. The correct average is :

The value of 2.33+0.0272.33-0.69+0.09

The circular measure of the included angle formed by the hour hand and minute hand of a clock at 3 PM will be

BE and CF are two altitudes of a triangle ABC. If AB = 6 cm , AC = 5 cm and CF = 4 cm , then the length of BE is