In a right triangle the legs have lenths of 8 and 15 what is the perimeter of this triangle

 The perimeter of the triangle is:  "40" .

Explanation:

The perimeter is the sum of the lengths of all sides ;
   which equals:  "8 + 15 + (length of hypotenuse) ,

We need to find the length of the hypotenuse in order the find the perimeter.


c² = a² + b² ;

c² = 8² + 15² ;

in which "c" is the length of the hypotenuse;  

Solve for "c" .

+√(c²) = √(8² + 15²) ;

   c = √ (64 + 225) ;

   c = +√289 

   c = 17 .

 So the perimeter of the triangle = 8 + 15 + 17 = 40 .

40 & 50 in the right corner are the complementary angles as when placed in a sum (added together) they make 90°