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Triangle ABC has vertices at A(−1 , 2), B(4, 2), and C(3, −1). Classify the triangle according to the side lengths.

A) equilateral
B) isosceles
C) right
D) scalene

Respuesta :

Answer:

B) Isosceles

Step-by-step explanation:

The given triangle has vertices at A(-1,2), B(4,2) and C(3,-1).

We must first determine the length of the sides of the triangle, before we can classify it.

We apply the distance formula to find length of the sides.

[tex]|AB|=\sqrt{(4--1)^2+(2-2)^2}[/tex]

[tex]\Rightarrow |AB|=\sqrt{(4+1)^2+(2-2)^2}[/tex]

[tex]\Rightarrow |AB|=\sqrt{5^2+(0)^2}[/tex]

[tex]\Rightarrow |AB|=\sqrt{25}[/tex]

[tex]\Rightarrow |AB|=5 units[/tex].

The length of side BC

[tex]|BC|=\sqrt{(3-4)^2+(-1-2)^2}[/tex]

[tex]\Rightarrow |BC|=\sqrt{(-1)^2+(-3)^2}[/tex]

[tex]\Rightarrow |BC|=\sqrt{1+9}[/tex]

[tex]\Rightarrow |BC|=\sqrt{10}[/tex]

The length of side AC

[tex]|AC|=\sqrt{(3--1)^2+(-1-2)^2}[/tex]

We simplify to obtain;

[tex]|AC|=\sqrt{(3+1)^2+(-3)^2}[/tex]

[tex]\Rightarrow |AC|=\sqrt{(4)^2+(-3)^2}[/tex]

[tex]|AC|=\sqrt{16+9}[/tex]

[tex]|AC|=\sqrt{25}[/tex]

[tex]|AC|=5\:units[/tex]

Since [tex]|AC|=5\:units=|AB|[/tex], the given triangle is an isosceles triangle.

The correct answer is

Answer:

B) isosceles

Step-by-step explanation: