Answer:
it is a right triangle 
Explanation:
confirm if it is a right triangle using  Pythagoras theorem
The Pythagoras theorem : a² + b² = c² 
where a = length 
b = base 
c = hypotenuse 
12² + 35²
144 + 1225 = 1369
square toot of 1369 is 37
so 
12² + 35² = 37²