Question 1: Calculate the total surface area of a cuboid with length 8 cm, width 3 cm, and height 4 cm. Use the net concept to verify the formula.

Answer: 136 cm²

Question 2: Construct a net for a cuboid with dimensions 10 cm by 5 cm by 3 cm. Sketch and label all faces correctly on the grid.

Answer: Correct net with all faces labeled

Question 3: Calculate the area of each face in the net of a cuboid measuring 12 cm x 6 cm x 4 cm.

Answer: 72 cm², 48 cm², 24 cm²

Question 4: Show that the surface area of a cuboid with dimensions 7 cm, 5 cm, and 3 cm is 94 cm² by summing the areas of the faces from its net.

Answer: 2(7×5 + 7×3 + 5×3) = 94 cm²

Question 1: A student draws a net of a cuboid but forgets to include one rectangular face. How does this mistake affect the calculated surface area? Explain your reasoning.

Answer: The surface area will be underestimated because one face's area is missing, leading to an incorrect total.

Question 2: Given a net with all faces correctly drawn but the student incorrectly labels a face as 20 cm² when it is actually 15 cm², how will this mistake impact the surface area calculation?

Answer: The total surface area computed will be incorrect, likely overestimated, due to mislabeling.

Question 3: A net is drawn with one face twice the size it should be. How does this error influence the surface area calculation? Explain.

Answer: The surface area will be overestimated because one face is counted twice its actual size.

Question 1: A packaging box in the shape of a cuboid has dimensions 30 cm x 20 cm x 10 cm. Construct its net and determine the total surface area for packaging material. Explain how understanding nets helps in designing packaging.

Answer: Net shows all faces; surface area = 2(30×20 + 20×10 + 30×10) = 2200 cm². Understanding nets aids in estimating material needed.

Question 1: Construct a net for a cuboid with an unusual dimension: 15 cm by 9 cm by 6 cm. Identify all faces and verify the net correctly represents the cuboid. Discuss common mistakes students make when drawing such nets.

Answer: Correct net with all faces labeled accurately; common mistake is missing a face or mislabeling dimensions.

Question 2: A student claims that the net of a cube with side length 4 cm will have only 4 faces visible when flattened. Is this correct? Explain your reasoning and correct the misconception.

Answer: Incorrect; a cube net has 6 faces. The misconception is that students forget some faces or think of a cube as a 2D shape.

Question 1: A student draws a net with all faces but mistakenly labels one rectangle as 50 cm² instead of the correct 30 cm². How does this mistake impact the total surface area? How should they correct it?

Answer: The total surface area will be overestimated; they should replace 50 cm² with 30 cm² in their calculation.

Question 2: Identify the mistake in the following reasoning: 'Since the length is 10 cm and width is 4 cm, the face area is 40 cm², so total surface area is 2×40 = 80 cm².' The student forgot to include the other faces. Correct the calculation.

Answer: They forgot to include the other two faces; total surface area = 2(10×4 + 10×5 + 4×5) (assuming dimensions), or they should sum all faces correctly.