in the figure below trianglePQM and triangleQRP are right triangles. the measure of lineQM is 6 and the measure of lineQP is 8. what is the measure of line PR?

in the figure below trianglePQM and triangleQRP are right triangles the measure of lineQM is 6 and the measure of lineQP is 8 what is the measure of line PR class=

Respuesta :

Answer:

Option 4 is correct. The length of PR is 6.4 units.

Step-by-step explanation:

From the given figure it is noticed that the triangle PQR and triangle MQR.

Let the length of PR be x.

Pythagoras formula

[tex]hypotenuse^2=base^2+perpendicular^2[/tex]

Use pythagoras formula for triangle PQM.

[tex]PM^2=QM^2+PQ^2[/tex]

[tex]PM^2=(6)^2+(8)^2[/tex]

[tex]PM^2=36+64[/tex]

[tex]PM^2=100[/tex]

[tex]PM=10[/tex]

The value of PM is 10. The length of PR is x, so the length of MR is (10-x).

Use pythagoras formula for triangle PQR.

[tex]PQ^2=QR^2+PR^2[/tex]

[tex](8)^2=QR^2+x^2[/tex]

[tex]64-x^2=QR^2[/tex]                   .....(1)

Use pythagoras formula for triangle MQR.

[tex]MQ^2=QR^2+MR^2[/tex]

[tex](6)^2=QR^2+(10-x)^2[/tex]

[tex]36=QR^2+x^2-20x+100[/tex]

[tex]36-x^2+20x-100=QR^2[/tex]        .... (2)

From equation (1) and (2) we get

[tex]36-x^2+20x-100=64-x^2[/tex]

[tex]20x-64=64[/tex]

[tex]20x=128[/tex]

[tex]x=6.4[/tex]

Therefore length of PR is 6.4 units and option 4 is correct.