Question

1. which one does not belong with the other three? explain.

Explanation:

Step1: Analyze angle relationships

• First group (top): Angles ∠1 and ∠2 seem complementary (sum to 90° if adjacent to right angle, but check others).
• Second group (A and B): \(50^\circ + 40^\circ = 90^\circ\) (complementary).
• Fourth group: \(65^\circ + 25^\circ = 90^\circ\) (complementary).
• Third group (∠3 and ∠4): They form a linear pair, so \(∠3 + ∠4 = 180^\circ\) (supplementary), not complementary.

Step2: Identify the odd one

The third figure (with ∠3 and ∠4) has supplementary angles, while others have complementary (sum 90°) angles.

Answer:

The third figure (with angles ∠3 and ∠4) does not belong. Others have complementary angles (sum 90°), but it has supplementary angles (sum 180°).