Question

104° (9x - 25)°

Explanation:

Step1: Determine the triangle type

This is an isosceles triangle (two sides are equal), so the two base angles are equal.

Step2: Use the triangle - angle - sum theorem

The sum of the interior angles of a triangle is \(180^{\circ}\). Let the base angles be \((9x - 25)^{\circ}\) each. Then \(104+(9x - 25)+(9x - 25)=180\).
Simplify the left - hand side: \(104 + 18x-50 = 180\), which is \(18x + 54=180\).
Subtract 54 from both sides: \(18x=180 - 54\), so \(18x = 126\).
Divide both sides by 18: \(x=\frac{126}{18}=7\).

Answer:

\(x = 7\)