Question

A straight line is an angle with ___ measurement.

• A. ${90}^o$
• B. ${180}^o$
• C. ${360}^o$
• D. ${45}^o$

Answer 1

The correct option is B ${180}^o$

Straight angles are formed when the legs are pointing in exactly opposite directions. The two legs then form a single straight line through the vertex of the angle. The measure of a flat angle is thus always ${180}^o$.