A4 Which of the following three lengths are not the lengths of the sides of a right triangle?
(A) $3 \mathrm{~cm}, 4 \mathrm{~cm}, 5 \mathrm{~cm}$
(B) $20 \mathrm{~cm}, 21 \mathrm{~cm}, 29 \mathrm{~cm}$
(C) $12 \mathrm{~cm}, 35 \mathrm{~cm}, 36 \mathrm{~cm}$
(D) $9 \mathrm{~cm}, 40 \mathrm{~cm}, 41 \mathrm{~cm}$
(E) $5 \mathrm{~cm}, 12 \mathrm{~cm}, 13 \mathrm{~cm}$
A4. Using the Pythagorean theorem, we determine that $12 \mathrm{~cm}, 35 \mathrm{~cm}$ and $36 \mathrm{~cm}$ are not the lengths of the sides of a right-angled triangle.