Answer:
not right - angled
Step-by-step explanation:
by the converse of Pythagoras' identity
if the square on the longest side is equal to the sum of the squares on the other 2 sides then the triangle is right
longest side = 13.7 , then 13.7² = 187.69
12.4² + 3.5² = 153.76 + 12.25 = 166.01
since 187.69 ≠ 156.01 then triangle is not right- angled
