Question

Point P is the incenter of ΔRST.

Point P is the incenter of triangle R S T. Lines are drawn from each point of the triangle to point P. Lines are drawn from point P to the sides of the triangle to form right angles and line segments P A, P B, and P C. The triangle has different angle measures.
Which must be true?

Line segment C P is-congruent-to line segment R P
Line segment B P is-congruent-to line segment P C
AnglePSC Is-congruent-to AnglePTC
AngleBPS Is-congruent-to AngleAPT

Answer 1

To analyze the relationships and properties of the incenter and the segments dropped to the sides of triangle \( RST \), we need to understand a few key concepts about the incenter.

1. **Incenter Definition**: The incenter \( P \) of a triangle is the point where the angle bisectors of the triangle meet. It is the center of the inscribed circle (incircle), which touches the sides of the triangle.

2. **Segments PA, PB, and PC**: The segments \( PA \), \( PB \), and \( PC \) are the perpendicular distances from the incenter \( P \) to the sides of triangle \( RST \).

We will evaluate the statements you provided:

1. **Line segment \( CP \) is congruent to line segment \( RP \)**: This statement is **not necessarily true**. The lengths from the incenter to the vertices are not congruent; rather, they depend on the angles and side lengths of the triangle.

2. **Line segment \( BP \) is congruent to line segment \( PC \)**: This statement is **not true** either, as it suggests specific relationships between the distances from the incenter to the sides. These lengths can vary depending on the triangle.

3. **Angle \( PSC \) is congruent to Angle \( PTC \)**: This statement is **not true**. Angles \( PSC \) and \( PTC \) are formed by different vertices of the triangle and do not have a specific relationship.

4. **Angle \( BPS \) is congruent to Angle \( APT \)**: This statement is **also not generally true**. These angles involve different vertices of the triangle and do not share a necessity of congruence.

Based on the properties of the incenter and the nature of angle bisectors and perpendiculars dropped from points to sides, none of the statements you provided must be true in general terms. Each relationship's validity would depend on the specific dimensions and angles of triangle \( RST \).

For a true relationship involving the incenter, one could state that \( PA \), \( PB \), and \( PC \) are equal in length to the radius of the incircle, but that doesn't show up in the statements provided.