Answer:
26°
Step-by-step explanation:
An obtuse triangle is a triangle that has one obtuse angle. Obtuse angle is an angle that is greater than 90 degrees but less than 180 degrees.
An isosceles triangle is a triangle that has two equal sides and angles.
Therefore, an obtuse isosceles triangle is a triangle with an obtuse angle and two equal sides that have two equal acute angles (angle less than 90° ).
Given:
The three angles of the triangle are given to be x°, x° and (10x−2) = 128°. The obtuse angle is 128°, the two x° are acute angles. We are not using equation 10x − 2 since the value of the obtuse angle has been given as 128°
The sum of angles in a triangle is 180°
∴ x° + x° + 128° = 180°
2x° = 180° - 128°
2x° = 52°
x° = 52° / 2
x° = 26°
The measurement of one of the acute angles is 26°
