The correct answer is (C):
Given, the non-parallel sides are equal.
Let the non-parallel sides be x cm each
x = √122+52 = 13
So, we have 6 faces, two are trapezoid faces and 4 are rectangular faces.
Area of 2 trapeziums
= 2[1/2(12)(10+20)]=360cm2
Area of 4 rectangles
= 2[13 × 20] + 20(20) + 10(20) = 1120 cm2
Total area = 1120 + 360 = 1480 cm2