In a right- angled triangle, one side is 8.3cm and another is 7.7. How do you find the perimeter of the triangle?

Question

1650 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-03-26T08:37:12

Two cases:

#27.32 \ "cm"#

#19.1 \ "cm"#

I see two cases in the following problem.

CASE 1: FINDING THE HYPOTENUSE

Let's say that you need to find the hypotenuse #c#, of the right-angled triangle.

Using Pythagoras' theorem, we got:

#a^2+b^2=c^2#

And so,

#8.3^2+7.7^2=c^2#

#c^2=128.18#

#c=sqrt(128.18)#

#=11.32#

Therefore, the perimeter will be #11.32+8.3+7.7=27.32# centimeters.

CASE 2: FINDING THE OTHER LEG

If the hypotenuse is already given, in this case, #8.3 \ "cm"#, we can easily find the other leg.

Using Pythagoras', #a^2+b^2=c^2#

#a^2=c^2-b^2#

Substitute in given values,

#a^2=8.3^2-7.7^2#

#=9.6#

#a=sqrt(9.6)#

#~~3.1#

And so, the perimeter here will be #3.1+8.3+7.7=19.1# centimeters.