Respuesta :

Isosceles triangles mean that 2 sides of the triangle are congruent. Since triangle RST is isosceles and P is its incenter, that means that PT and PR must be congruent, also. PRT is an isosceles triangle.

Answer:

[tex]\Delta \text{RPT is an isosceles triangle}[/tex]

Step-by-step explanation:

As in the triangle RST,

[tex]RS=ST\ \ \ \Rightarrow m\angle SRT=m\angle STR[/tex]

Because if in a triangle two angles equal one another, then the sides opposite the equal angles also equal one another.

Incenter is obtained by the Intersection of a triangle's three angle bisectors and it is equidistant from the three sides of the triangle.

So, RP and TP are the angle bisectors of ∠R and ∠T respectively.

[tex]\Rightarrow \dfrac{m\angle SRT}{2}=\dfrac{m\angle STR}{2}[/tex]

[tex]\Rightarrow m\angle PRT=m\angle PTR[/tex]

[tex]\Rightarrow PR=PT[/tex]

[tex]\Rightarrow \Delta \text{RPT is an isosceles triangle}[/tex]