G13: Plans & Elevations
Construct and interpret plans and elevations of 3D shapes
Construct and interpret plans and elevations of 3D shapes
Draw the plan view of a cuboid 4 cm × 3 cm × 2 cm (length × width × height).
Solution:
Looking from above, you see the length and width.
Plan view is a rectangle 4 cm × 3 cm.
The height (2 cm) is not visible from above.
Draw the front elevation of a cuboid 4 cm × 3 cm × 2 cm, viewed from the 4 cm × 2 cm face.
Solution:
Front elevation is a rectangle 4 cm × 2 cm.
This shows the height and length of the front face.
Draw the side elevation of a cuboid 4 cm × 3 cm × 2 cm, viewed from the side (3 cm × 2 cm face).
Solution:
Side elevation is a rectangle 3 cm × 2 cm.
A shape has: Plan view = square, Front elevation = rectangle, Side elevation = rectangle. What could the shape be?
Solution:
Plan view = square → top face is square
Front and side = rectangles → could be a square-based prism or cube
If all views are squares → cube
An L-shaped block is made from two cuboids. Draw the plan, front and side elevations.
Solution:
Plan view: Look down - shows L-shape from above
Front elevation: Look from front - shows height and width, accounting for different heights
Side elevation: Look from side - shows height and depth
Tip: Use squared paper and count squares carefully.
Plan = circle, Front elevation = rectangle, Side elevation = rectangle. What is the shape?
Solution:
Plan = circle → circular base
Front = rectangle → vertical sides
Side = rectangle → confirms vertical sides
This is a cylinder.
Q1: What does the plan view show?
Q2: A cuboid has dimensions 5 cm × 4 cm × 3 cm. Draw the front elevation (viewing the 5 cm × 3 cm face).
Q3: What 3D shape has a circular plan view and a rectangular front elevation?
Q4: A triangular prism has a triangular cross-section. What shape is the front elevation?
Q5: If plan view = triangle, what could the 3D shape be?
A shape made from cubes has the front elevation: 3 squares tall on the left, 1 square tall on the right. The side elevation: 2 squares tall on the left, 1 square tall on the right. What is the minimum number of cubes needed?
Solution: Front shows 4 visible squares (3+1). Side shows 3 visible squares (2+1). The minimum arrangement uses 5 cubes: 3 stacked at the back-left (seen as 3 in front, 2 in side), 1 at back-right (seen as 1 in front, 1 in side), and 1 at front-left row 2 height (seen as part of the 3-high column from front, part of 2-high from side). Minimum = 5 cubes.
1. Wrong: Drawing the front elevation from a different direction than specified Correct: Always check which direction is the "front". The front elevation is what you see looking from the front face of the object as given in the question.
2. Wrong: Forgetting to show hidden edges with dashed lines Correct: Edges that are behind other faces (not visible from the viewing direction) must be drawn as dashed lines, not omitted.
3. Wrong: Confusing the plan view with the front elevation Correct: Plan view is from ABOVE (bird's eye view). Front elevation is from the FRONT (eye level). They show completely different information about the same object.
6 marks: A solid is made from a cuboid 8 cm x 4 cm x 6 cm with a hemispherical depression of radius 2 cm cut from the top face. (a) Draw the plan view of the solid. (b) Draw the front elevation. (c) Calculate the volume of the solid, giving your answer to 3 significant figures.
(a) Plan view: a rectangle 8 cm x 4 cm with a circle of radius 2 cm visible inside (the hemisphere seen from above appears as a full circle).
(b) Front elevation: a rectangle 8 cm x 6 cm with a semicircular cut-out of radius 2 cm at the top centre.
(c) Cuboid volume = 8 x 4 x 6 = 192 cm cubed. Hemisphere volume = 1/2 x 4/3 x pi x 2 cubed = 2/3 x pi x 8 = 16.76 cm cubed. Solid volume = 192 - 16.76 = 175.24 = 175 cm cubed (3 s.f.).
Mark scheme: M1 plan with circle, A1 correct plan, M1 front with semicircle, A1 correct elevation, M1 volume calculations, A1 175 cm cubed
A student sees the plan view of a shape: a 4x3 rectangle. The front elevation: a 4x2 rectangle. The side elevation: a 3x2 rectangle.
(a) Could this be a cuboid? If so, what are its dimensions?
(b) The student says "The plan view tells me the height is 2." Is this correct?
(c) Another shape has a circular plan view but a triangular front elevation. Describe a possible 3D shape.
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