Which of the following angles in the diagram are acute?

(A) ∠A (B) ∠C (C) ∠B + ∠C (D) ∠D

Q. A, B, C and D are four angles at a point so that $A+B+C+D=$ 4 right angles, out of these A and B are acute angles while C and D are obtuse angles. Which of the following relations may be true
1. $A+B=C+D$
2. $A+C=B+D$
3. $A+D=B+C$

Q. A, B, C and D are four angles at a point so that A + B + C + D = 4 right angles, out of these A and B are acute angles while C and D are obtuse angles. Which of the following relations may be true?
1. A + B = C + D
2. A + C = B + D
3. A + D = B + C

Q. In ∆ABC, ∠B = 35°, ∠C = 65° and the bisector AD of ∠BAC meets BC at D. Then, which of the following is true?
(a) AD > BD > CD
(b) BD > AD > CD
(c) AD > CD > BD
(d) None of these

Q. If $a,b,c$ and $d$ are in proportion, which of the following are true?

Q. In the given figure, ABCD is a cyclic quadrilateral in which AC and BD are its diagonals. If ∠DBC = 55° and ∠BAC = 45°, find ∠BCD.