A right triangle has one angle that measures $80°$. What is the measure of the other acute angle?

• A. $20°$
• B. $90°$
• C. $10°$
• D. $80°$

Answer: (C)

Verified step by step guidance

1. Recall that the sum of the interior angles in any triangle is always \$180^\circ$.
2. In a right triangle, one angle is always \$90^\circ$ by definition.
3. Given one of the other angles is \$80^\circ$, use the angle sum property to find the remaining angle.
4. Set up the equation: \$90^\circ + 80^\circ + \text{other angle} = 180^\circ$.
5. Solve for the other angle by subtracting the sum of the known angles from \$180^\circ\(: \)\text{other angle} = 180^\circ - 90^\circ - 80^\circ$.