71.

If a = 25,  b = 15,  c = -10, then the value of 

• 30

• -15

• -30

• -30

A, B, C are three points on a circle. The tangent at A meets BC produced at T, . The angle subtended by BC at the centre of the circle is

• 84°

• 92°

• 96°

• 96°

If the length of a chord of a circle at a distance of 12cm from the centre is 10 cm, then the diameter of the circle is

• 13 cm

• 15 cm

• 26 cm

• 26 cm

In ΔABC, P and Q are the middle points of the sides AB and AC respectively. R is a point on the segment PQ such that PR : RQ = 1 : 2. If PR = 2cm, the BC =  

• 4 cm

• 2 cm

• 12 cm

• 12 cm

If O is the circumcentre of ΔABC and , then the  is equal to

• 55°

• 110°

• 70°

• 70°

IF I is the incentre of ΔABC and , then ΔABC is 

• acute angled

• equilateral

• right angled

• right angled

If  then the value of 

• 1

• -1

• 0

• 0

The value of
 is

• -1

• 

• 0

• 0

If  then the value of  is

If  then the value of  is equal to