1. The problem is to classify triangles by their angles and sides. 2. For angles: - An obtuse triangle has one angle greater than 90°. - An acute triangle has all angles less than 90°. 3. For sides: - Equilateral: all three sides equal. - Isosceles: exactly two sides equal. - Scalene: all sides different. 4. Angle classifications: - Triangle with angles 92° and 38° is obtuse because 92° > 90°. - Triangle with angles 60° and 80° is acute because both < 90°. - Triangle with angle 70° is acute, not obtuse (70° < 90°), so the label "obtuse" is incorrect. 5. Side classifications: - Triangle 7: sides 4 cm, 5 cm, 6 cm. All sides different, so scalene, not equilateral. - Triangle 8: sides 4.5 in, 7.5 in, 6.5 in. All sides different, so scalene, not isosceles. - Triangle 9: sides 9 yd, 9 yd, 12 yd. Two sides equal, so isosceles, not scalene. - Triangle 10: sides 4.5 cm, 4.5 cm, 4.5 cm. All sides equal, so equilateral, not isosceles. - Triangle 11: sides 4 cm, 12 cm, 11 cm. All sides different, so scalene. - Triangle 12: sides 3.5 cm, 6 cm, 3.5 cm. Two sides equal, so isosceles, not scalene. Final classifications: - Angles: 92° 38° obtuse correct; 60° 80° acute correct; 70° acute (not obtuse). - Sides: 7: scalene 8: scalene 9: isosceles 10: equilateral 11: scalene 12: isosceles This corrects the given labels based on definitions.