Unit 3: Geometry and Trigonometry

Topic 3.18: Lines & planes (HL only) Questions

Practice 20 exam-style questions for IB Math AA SL Topic 3.18. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.

11 mark
2026
A line and a plane in 3D, in general position, intersect in:
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21 mark
2026
To get the intersection POINT after finding λ = 3, you substitute λ = 3 into:
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31 mark
2026
Two non-parallel planes intersect in:
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41 mark
2026
The angle between two planes equals the angle between:
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5Find1 mark
2026
Find the coordinates of the point on the line when .
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61 mark
2026
If a line's direction d satisfies d·n = 0 (n is the plane's normal), the line is:
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71 mark
2026
For r = (0,0,0) + λ(1,1,1) and plane x + y + z = 6, the parameter at the intersection is:
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8Find4 marks
2026
The line r = (2, 1, 0) + λ(1, −1, 2) meets the plane 2x + y − z = 5 at a point P. Find the coordinates of P.
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9Find4 marks
2026
Find the acute angle between the planes Π₁: 2x − y + 2z = 5 and Π₂: x + 2y + 2z = 3, giving your answer to one decimal place.
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101 mark
2026
Planes with normals n₁ = (1, 0, 0) and n₂ = (0, 1, 0) meet at an angle of:
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111 mark
2026
For the angle between a line and a plane you should use:
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121 mark
2026
To get a POINT on the line where two planes meet, a quick method is to:
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131 mark
2026
Substituting a line into a plane leaves '5 = 5'. The line:
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14Find4 marks
2026
Find the exact value of cos θ for the acute angle between the planes x + y = 2 and y + z = 5.
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15Find4 marks
2026
The line r = (4, 0, −2) + λ(−1, 3, 1) crosses the plane 3x + y + 2z = 6 at point Q. Find Q.
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16Show that1 mark
2026
Show that the line is parallel to the plane.
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17Show that3 marks
2026
Show that these planes are parallel and never meet.
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18Find3 marks
2026
Find the angle between the planes.
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19Find6 marks
2026
Find the coordinates of the point where the line meets the plane.
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20Find6 marks
2026
Find a vector equation of their line of intersection.
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