A right triangle has one angle that measures $20°$. What is the measure of the other acute angle?

• A. $80°$
• B. $70°$
• C. $90°$
• D. $60°$

Answer: (B)

Verified step by step guidance

1. Recall that the sum of the interior angles in any triangle is \$180^\circ$.
2. Since the triangle is a right triangle, one of its angles measures \$90^\circ$.
3. Let the given acute angle be \$20^\circ\( and the other acute angle be \)x$ degrees.
4. Set up the equation for the sum of angles: \$90^\circ + 20^\circ + x = 180^\circ$.
5. Solve for \(x\) by subtracting \$90^\circ\( and \)20^\circ\( from \)180^\circ\(: \)x = 180^\circ - 90^\circ - 20^\circ$.