ABC is a triangle inscribed in a circle with centre O. Let a = BAC, where 45° < a < 90°. Let p = BOC. Which one of the following is correct ?
If a flag-staff of 6m height placed on the top of a tower throws a shadow of 2 m along the ground,then what is the angle that the sun makes with the ground?
600
450
15
A spherical balloon of radius r subtends an angle a at the eye of an observer, while the angle of elevation of its centre is . What is the height of the centre of the balloon (neglecting the height of the observer) ?
A.
In right angle
Suppose cos(A) is given. If only one value of is possible, then A must be :
An odd multiple of 900
A multiple of 90°
An odd multiple of 1800
A multiple of 180°