The sides of four triangles are given below. Which of them forms a right triangle ?
(A) 20 cm, 22 cm, 24 cm
(B) 15 cm, 32 cm, 37 cm
(C) 11 cm, 60 cm, 61 cm
(D) 6 cm, 8 cm, 10 cm

For the triangle to be a right-angled triangle, the sum of squares of the two smaller sides is equal to the square of the largest side. 

(A) 20 cm, 22 cm, 24 cm
$$20^2+22^2=400+484=884$$
$$24^2=576$$
Not a right angled triangle

(B) 15 cm, 32 cm, 37 cm
$$15^2+32^2=225+1024=1249$$
$$37^2=1369$$
Not a right angled triangle

(C) 11 cm, 60 cm, 61 cm
$$11^2+60^2=121+3600=3721$$
$$61^2=3721$$
This is a right angled triangle

(D) 6 cm, 8 cm, 10 cm
$$6^2+8^2=36+64=100$$
$$10^2=100$$
This is a right angled triangle