Question

triangle a triangle b triangle c triangle d acute acute acute acute obtuse obtuse obtuse obtuse right right right right

Explanation:

Step1: Recall triangle type definitions

Acute: all angles < \(90^{\circ}\). Right: one angle = \(90^{\circ}\). Obtuse: one angle > \(90^{\circ}\).

Step2: Analyze Triangle A

Angles \(60^{\circ},60^{\circ},60^{\circ}\) (sum \(180^{\circ}\)). All < \(90^{\circ}\) → Acute.

Step3: Analyze Triangle B

One angle \(90^{\circ}\) → Right.

Step4: Analyze Triangle C

One angle \(120^{\circ}>90^{\circ}\) → Obtuse.

Step5: Analyze Triangle D

One angle \(110^{\circ}>90^{\circ}\) → Obtuse.

Answer:

Triangle A: Acute, Triangle B: Right, Triangle C: Obtuse, Triangle D: Obtuse