Q. If the length of a chord of a circle at a distance of 12 cm from the Centre is 10 cm, then the diameter of the circle is-
a. 13 cm
b. 15 cm
c. 26 cm
d. 30 cm
Ans :
We know that OA = ?OM2 + AM2
= ?122 + 52 = 13
We know Diameter of the circle = 2*OA
= 2*13 = 26cm
Q. In &Delta ABC, 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 = 2 cm, then BC =
a. 4 cm
b. 2 cm
c. 12 cm
d. 6 cm
a. 4 cm
b. 2 cm
c. 12 cm
d. 6 cm
We know that PR/RQ = ½
But, PR = 2cm
RQ = 2*PR
= 4cm
We know PQ = PR + RQ
= 2 + 4 = 6 cm
We know BC = 2*PQ = 12CM
Q. The value of cot ?/20 cot 3? /20 cot 5? /20 cot 7? /20 cot 9? /20 is-