Question

triangles below acute, obtuse, or right?
triangle a
triangle b
triangle c
triangle d
○ acute
○ obtuse
○ right
○ acute
○ obtuse
○ right
○ acute
○ obtuse
○ right
○ acute
○ obtuse
○ right

Explanation:

Step1: Classify Triangle A

Triangle A has a $90^\circ$ (right) angle.

Step2: Classify Triangle B

Sum of angles: $50^\circ+55^\circ+75^\circ=180^\circ$, all angles $<90^\circ$.

Step3: Classify Triangle C

Triangle C has a $90^\circ$ (right) angle.

Step4: Classify Triangle D

Triangle D has a $110^\circ$ angle ($>90^\circ$, obtuse).

Answer:

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