Question

step by step explanation please​

Answer 1

Answer:

11-(d) 60°aaaaaa@aaaaaaaaaaa

Answer 2

Answer:

answer of (10)

is option C i.e. 30°

explanation-

if u draw radius from o to B and C

thus OBC forms a equilateral triangle

as BC is also equal to radius..

then the central angle will be equal to 60°

and we know that the angle at circumference of circle by the chord is equal to the half of angle formed at centre by the same chord..

here the central angle is 60°

thus angle BAC = 1/2 x 60 = 30°

answer of (12)

is option C i.e. 80°

explanation-

join A to C

then AC is chord

as we know that the angle at circumference of circle by the chord is equal to the half of angle formed at centre by the same chord..

here the angle at circumference is 40°

thus the angle at centre = 2 × 40 = 80°

hope this will help you