Question

are the 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: Recall angle - type definitions

An acute - angled triangle has all angles less than 90°. A right - angled triangle has one angle equal to 90°. An obtuse - angled triangle has one angle greater than 90°.

Step2: Analyze Triangle A

Triangle A has angles 30°, 60°, and 90°. Since it has a 90° angle, it is a right - angled triangle.

Step3: Analyze Triangle B

Triangle B has angles 35°, 30°, and 115°. Since it has a 115° angle (which is greater than 90°), it is an obtuse - angled triangle.

Step4: Analyze Triangle C

Triangle C has angles 50°, 55°, and 75°. Since all angles are less than 90°, it is an acute - angled triangle.

Step5: Analyze Triangle D

Triangle D has angles 30°, 40°, and 110°. Since it has a 110° angle (which is greater than 90°), it is an obtuse - angled triangle.

Answer:

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