Let the edge of each cube be a cm. Volume of each cube = a3 cm3 It is given that the volume of each cube is 27 cm3. ∴ a3 = 27= (3)3 ⇒ a = 3 Thus, length of each edge of the cube = 3 cm When two cubes are joined end-to-end, the solid obtained is a cuboid whose length, breadth and height are 6 cm, 3 cm and 3 cm respectively. This can be diagrammatically shown as follows: Surface area of the cuboid = 2 (lb + bh + hl) = 2 (6 cm × 3 cm + 3 cm × 3 cm + 3 cm × 6 cm) = 2 × 45 cm2 = 90 cm2 Thus, the surface area of the resulting cuboid is 90 cm2.
Option 3 : 5488 cm3 and 1960 cm2
Given: Two cubes of edge 14 cm each are joined end to end to form a cuboid. Formula Used: Volume of a cuboid = lbh Total Surface Area of cuboid = 2(lb + bh + hl) Where l = length, b = breadth and h = height Calculation: The final object becomes a cuboid. For the cuboid l = 28 cm b = 14 cm h = 14 cm Volume of a cuboid = lbh = 28 × 14 × 14 = 5488 cm3 Total Surface Area of cuboid = 2 (28 × 14 + 14 × 14 + 14 × 28) = 2 × 14 ( 28 + 14 + 28 ) = 1960 cm2 India’s #1 Learning Platform Start Complete Exam Preparation
Video Lessons & PDF Notes Trusted by 2,78,00,541+ Students > Solution Dimensions of the cuboid formed : l = 12 cm b = 4 cm h = 4 cm Total surface area of the cuboid formed = 2 (l×b+b×h+l×h) = 2(12×4+4×4+4×12)=224 cm2 Suggest Corrections 2 |