Question

In a right triangle, one angle is 30 degrees. What is the measure of the other non-right angle?

• A. 30 degrees
• B. 45 degrees
• C. 60 degrees
• D. 75 degrees

Hint:

In a right triangle, the two non-right (acute) angles are complementary, which means their sum is always 90 degrees. So, if one acute angle is given, you can find the other by simply subtracting the given angle from 90. Here, \( 90^\circ - 30^\circ = 60^\circ \).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The sum of the interior angles in any triangle is always 180 degrees. A right triangle is a special type of triangle that has one angle exactly equal to 90 degrees.
Step 2: Detailed Explanation:
Let the three angles of the triangle be A, B, and C.
We know that \( A + B + C = 180^\circ \).
Since it is a right triangle, one of the angles is \( 90^\circ \). Let's say \( A = 90^\circ \).
We are given that another angle is \( 30^\circ \). Let's say \( B = 30^\circ \).
We need to find the measure of the third angle, C.
Substitute the known values into the sum equation:
\[ 90^\circ + 30^\circ + C = 180^\circ \] \[ 120^\circ + C = 180^\circ \] To find C, subtract \( 120^\circ \) from both sides:
\[ C = 180^\circ - 120^\circ \] \[ C = 60^\circ \] Step 3: Final Answer:
The measure of the other non-right angle is 60 degrees.