Question

classify the triangles by their sides and angles. obtuse isosceles acute scalene

Explanation:

Step1: Analyze the properties of an obtuse isosceles triangle

An obtuse isosceles triangle has one angle greater than \(90^{\circ}\) (obtuse angle) and two sides of equal length (isosceles). Looking at the given triangles, the second triangle has one obtuse angle and two equal - length sides (marked with the same symbol).

Step2: Analyze the properties of an acute scalene triangle

An acute scalene triangle has all angles less than \(90^{\circ}\) (acute angles) and all sides of different lengths (scalene). The fourth triangle has all acute angles and no sides of equal length (no side - marking symbols are repeated).

Answer:

Obtuse Isosceles: Second triangle; Acute Scalene: Fourth triangle