✎ TruMath Assignment

MCV4U Equations of Lines & Planes
Grade 12 Unit 7 — practice questions with full solutions

Vector, parametric, symmetric and scalar equations, intersections, distances and angles — where vectors turn back into geometry.

Free MCV4U equations of lines & planes practice for Grade 12 students in Ontario. These 6 questions cover the same material as a typical unit test or exam review on this topic, and every one comes with a complete worked solution — not just an answer key. Useful whether you are preparing for a MCV4U unit test, catching up on a lesson, or reviewing before the final exam.
MCV4U · Grade 12 Geometry and Algebra of Vectors 5 core 1 challenge
1Core
Write the vector equation and the parametric equations of the line through (1, −2, 3) with direction vector (2, 1, −4).
Show the full solution
  1. A vector equation has the form r = r0 + tm, where r0 is a point on the line and m its direction.
  2. So r = (1, −2, 3) + t(2, 1, −4).
  3. Reading off each coordinate separately gives the parametric form.
  4. x = 1 + 2t, y = −2 + t, z = 3 − 4t.
Final answerr = (1, −2, 3) + t(2, 1, −4); x = 1 + 2t, y = −2 + t, z = 3 − 4t
2Core
Write the symmetric equation of the line through (1, −2, 3) with direction vector (2, 1, −4).
Show the full solution
  1. Start from the parametric equations and solve each for t.
  2. From x = 1 + 2t: t = (x − 1) ÷ 2.
  3. From y = −2 + t: t = y + 2.
  4. From z = 3 − 4t: t = (z − 3) ÷ (−4).
  5. Setting the three expressions equal gives the symmetric form.
Final answer(x − 1)⁄2 = (y + 2)⁄1 = (z − 3)⁄(−4)
3Core
Find the scalar equation of the plane with normal vector (3, −1, 2) passing through the point (2, 0, −1).
Show the full solution
  1. A plane with normal (A, B, C) through (x0, y0, z0) satisfies A(xx0) + B(yy0) + C(zz0) = 0.
  2. Substitute: 3(x − 2) − 1(y − 0) + 2(z + 1) = 0.
  3. Expand: 3x − 6 − y + 2z + 2 = 0.
  4. Collect constants: 3xy + 2z − 4 = 0.
Final answer3xy + 2z − 4 = 0
4Core
Find the point where the line x = 1 + 2t, y = −2 + t, z = 3 − 4t meets the plane 3xy + 2z − 4 = 0.
Show the full solution
  1. Substitute the parametric expressions into the plane equation.
  2. 3(1 + 2t) − (−2 + t) + 2(3 − 4t) − 4 = 0.
  3. Expand: 3 + 6t + 2 − t + 6 − 8t − 4 = 0.
  4. Collect: 7 − 3t = 0, so t = 73.
  5. Substitute back: x = 1 + 143 = 173, y = −2 + 73 = 13, z = 3 − 283 = −193.
Final answer(173, 13, −193)
5Core
Find the distance from the point (4, 1, −2) to the plane 2xy + 2z − 6 = 0.
Show the full solution
  1. Distance from (x1, y1, z1) to Ax + By + Cz + D = 0 is |Ax1 + By1 + Cz1 + D| ÷ √(A2 + B2 + C2).
  2. Numerator: |2(4) − 1 + 2(−2) − 6| = |8 − 1 − 4 − 6| = |−3| = 3.
  3. Denominator: √(4 + 1 + 4) = √9 = 3.
  4. Distance = 3 ÷ 3 = 1.
Final answer1 unit
6Challenge
Find the acute angle between the planes with normal vectors (1, 2, −1) and (2, −1, 3), to one decimal place.
Show the full solution
  1. The angle between two planes equals the angle between their normals.
  2. Dot product: (1)(2) + (2)(−1) + (−1)(3) = 2 − 2 − 3 = −3.
  3. |n1| = √6 ≈ 2.4495 and |n2| = √14 ≈ 3.7417.
  4. cos θ = −3 ÷ (2.4495 × 3.7417) ≈ −0.3273, giving θ ≈ 109.1°.
  5. Because the angle is obtuse, the acute angle between the planes is 180° − 109.1° ≈ 70.9°.
Final answer≈ 70.9°

MCV4U Equations of Lines & Planes — common questions

Short answers to the things students ask most about this unit.

What is the difference between vector, parametric and symmetric equations of a line?

They carry the same information in different formats: the vector form uses a point plus a multiple of the direction, the parametric form lists each coordinate separately, and the symmetric form eliminates the parameter.

How do I find where a line meets a plane?

Substitute the line's parametric expressions into the scalar equation of the plane, solve the resulting equation for the parameter, then substitute that value back into the line to get the point.

Practice is step one

The classes teach the method behind every one of these.

The solutions above show the steps. The classes teach how to think about the problem in the first place — interactive, and worked through at the student’s own pace. Try 3 complete classes free — no payment required to begin.

Try 3 Classes Free →