What is the area of the triangle whose vertices are X(−5, −1)) , Y(−5, −10)) , and Z(−9, −7) ?

____Units sqared

Respuesta :

XY = −1−(−10) = 9 
(line x = −5) = −5−(−9) = 4

Area = 1/2 * 9 * 4 = 18

Answer:

17.96 units squared

Step-by-step explanation:

Refer the attached figure .

Point X =  (−5, −1)

Point Y=(−5, −10)

Point Z=(−9, −7)

In ΔXYZ , to find the length of sides we will use distance formula.

[tex]d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

Length of XY

Point X = [tex](x_1,y_1)=(-5,-1)[/tex]

Point Y= [tex](x_2,y_2)=(-5,-10)[/tex]

[tex]XY=\sqrt{(-5-(-5))^2+(-10-(-1))^2}[/tex]

[tex]XY=\sqrt{(0)^2+(-9)^2}[/tex]

[tex]XY=\sqrt{81}[/tex]

[tex]XY=9[/tex]

Length of YZ

Point Y= [tex](x_1,y_1)=(-5,-10)[/tex]

Point Z = [tex](x_2,y_2)=(-9,-7)[/tex]

[tex]YZ=\sqrt{(-9-(-5))^2+(-7-(-10))^2}[/tex]

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

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

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

[tex]YZ=\sqrt{25}[/tex]

[tex]YZ=5[/tex]

Length of XZ

Point X = [tex](x_1,y_1)=(-5,-1)[/tex]

Point Z = [tex](x_2,y_2)=(-9,-7)[/tex]

[tex]XZ=\sqrt{(-9-(-5))^2+(-7-(-1))^2}[/tex]

[tex]XZ=\sqrt{(-4)^2+(-6)^2}[/tex]

[tex]XZ=\sqrt{16+36}[/tex]

[tex]XZ=\sqrt{52}[/tex]

[tex]XZ=7.2[/tex]

So, to find the area of triangle we will use heron's formula .

[tex]Area =\sqrt{s(s-a)(s-b)(s-c)}[/tex]

Where [tex]s=\frac{a+b+c}{2}[/tex]

a,b,c are sides of triangle

a=9

b=5

c=7.2

[tex]s=\frac{9+5+7.2}{2}[/tex]

[tex]s=10.6[/tex]

[tex]Area =\sqrt{10.6(10.6-9-a)(10.6-5)(10.6-7.2)}[/tex]

[tex]Area =\sqrt{322.9184}[/tex]

[tex]Area =17.96[/tex]

Hence the area of triangle is 17.96 units squared

Ver imagen wifilethbridge