A right-angled triangle has perpendicular sides of length 6cm and 8cm, and a hypoteneuse of 2y cm. Find the length of y.
By Pythagoras' Theorem:(2y)2= 62 + 824y2 = 36 +64y2 = 9 + 16y2 = 25y = ±5However, dimensions can only have a positive value. Therefore y=5
