Triangle QRS is a right triangle with one angle measuring $90°$ and another angle measuring $38°$. What is the measure of the third angle in degrees?

• A. $38°$
• B. $52°$
• C. $90°$
• D. $128°$

Answer: (B)

Verified step by step guidance

1. Recall that the sum of the interior angles in any triangle is always \(180^\circ\).
2. Identify the given angles in triangle QRS: one angle is \(90^\circ\) (right angle) and another angle is \(38^\circ\).
3. Set up the equation for the sum of angles: \(90^\circ + 38^\circ + \text{third angle} = 180^\circ\).
4. Combine the known angles: \(128^\circ + \text{third angle} = 180^\circ\).
5. Solve for the third angle by subtracting \(128^\circ\) from \(180^\circ\): \(\text{third angle} = 180^\circ - 128^\circ\).