Find the angles which is equal to its supplement?(a) 90° (b) 108° (c) 45° (d) 180°

Break Down the Problem

1. Understanding Supplementary Angles: Supplementary angles are two angles whose sum is 180°.
2. Formulating the Equation: Let the angle be $x$. Therefore, the equation can be set up as: $x + (180° - x) = 180°$ This implies $x = 180° - x$.

Relevant Concepts

1. Setting Up the Equation: $x + (180° - x) = 180°$ Leads to: $2x = 180°$

2. Solving for x: To find the angle, solve using the equation $2x = 180°$.

Analysis and Detail

1. Solving the Equation Step by Step: $2x = 180°$ Divide both sides by 2: $x = \frac{180°}{2} = 90°$

Verify and Summarize

1. Checking the Found Angle: Verify if 90° is indeed equal to its supplement. $180° - 90° = 90°$ Therefore, the angle is equal to its supplement.

Final Answer

The angle which is equal to its supplement is $\boxed{90°}$.