Final answer:
A regular decagon has ten sides and ten angles, all of which are congruent. Therefore, options B and D are true for a regular decagon.
Step-by-step explanation:
The question asks which statements are true regarding a regular decagon. A regular decagon is a ten-sided polygon where all sides and angles are congruent.
- B). It has ten sides. This is true. By definition, a decagon has ten sides.
- D).It has more sides than a pentagon. This is also true. A pentagon has five sides, which is fewer than a decagon's ten sides.
The other options provided can be evaluated as follows:
- A). It has nine angles. This is false. A regular decagon, like any other decagon, has ten angles.
- C). Five of its sides are congruent. This statement is misleading. While it is true that any five sides of a regular decagon would be congruent to one another (as all sides of a regular decagon are congruent), the implication that only five sides are congruent is incorrect; in reality, all ten sides are congruent.