Which of the following angles in the diagram are acute?

Q.

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. A, B, C and D are four angles at a point so that $A+B+C+D=4$ rightangles, outof these A and B are acute angles while C and D are obtuse angles. Which of the following relations may be true?

1. 2 and 3 only
2. 1 and 3 only
3. 1 and 2 only
4. 3 only

Q.

Draw diagrams illustrating each of the following situation:

(a) Three straight lines which do not pass through a fixed point.

(b) A point and rays emanating from that point such that the angle between any two adjacent rays is an acute angle.

(c) Two angles which are not adjacent angles, but still supplementary.

(d) Three points in the plane which are equidistant from each other.