What type of triangle is formed by joining the points D(7, 3), E(8, 1), and
F(4, -1)?
equilateral triangle
isosceles triangle
right triangle
acute scalene triangle
obtuse scalene triangle

Respuesta :

Right triangle would be the answer your looking for>

Answer:

Option C is the answer.

Step-by-step explanation:

A triangle is given with vertices as D(7,3) E(8,1) and F(4,-1).

Now side DE =  [tex]\sqrt{(7-8)^{2}+(3-1)^{2}[/tex]

=[tex]\sqrt{1^{2}+2^{2}}=\sqrt{1+4}=\sqrt{5}[/tex]

Side EF =[tex]\sqrt{(8-4)^{2} +(1+1)^{2} } = \sqrt{4^{2}+2^{2} }[/tex]

= [tex]\sqrt{16+4}= \sqrt{20}[/tex]

Side DF =[tex]\sqrt{(7-4)^{2}+(3+1)^{2} } = \sqrt{3^{2}+4^{2}}[/tex]

[tex]=\sqrt{16+9} = \sqrt{25}[/tex]

Now for right angle triangle

DF²≡ EF² + DE²

[tex](\sqrt{5})^{2} + (\sqrt{20})^{2}= 5^{2}[/tex]

25 = 25

Therefore, the given triangle is a right angle triangle.

Option C is the answer.