Circles Solved Questions Page-2

For questions 9-11 use the figure below
circle-questions
9) The circle with centre O is the circum-circle of the triangle
(A) ∠ABC
(B) ∠DEF
(C) ∠AGH
(D) none of these

10) The circle with centre O is the inscribed of the triangle ___
(A) ∠ABC
(B) ∠DEF
(C) ∠AGH
(D) none of these

11) The circle with centre O is the escribed of the triangle
(A) ∠ABC
(B) ∠DEF
(C) ∠AGH
(D) none of these

For questions 12-14 use the figure below
circle-questions
A circle centre at C touches DE at B and m∠ABE = 40°.

12) Find m∠CBA
(A) 40°
(B) 50°
(C) 80°
(D) 90°

13) Find m∠BAC
(A) 40°
(B) 50°
(C) 80°
(D) 90°

14) Find m∠ACB
(A) 40°
(B) 50°
(C) 80°
(D) 90°

15) In the figure below the area of the shaded sector is 85% of the area of the entire circle, what is the value of x?
circle-questions

(A) 15
(B) 30
(C) 45
(D) 54

16) The circumference of a circle is a π units, and the area of the circle is b π square units. If a = b, what is the radius of the circle?
(A) 1
(B) 2
(C) 3
(D) π