Topic Details (Notes format)

How to Write Equations of Parallel and Perpendicular Lines

Subject: Mathematics

Book: Maths Mastery

Two lines are parallel if they share the same slope but have different y-intercepts (m₁ = m₂). Perpendicular lines’ slopes are negative reciprocals (m₁ × m₂ = –1). For instance, if a line has slope 2, a parallel line also has slope 2, while a perpendicular line’s slope is –1/2. In slope-intercept form y = mx + b, changing b shifts the line parallelly, and switching to the negative reciprocal changes its orientation to perpendicular. In fields like architecture or geometry proofs, this concept ensures accurate angle construction and parallel design alignment. Practice with slope forms cements your ability to interpret and create consistent geometric relationships.

Practice Questions

A rectangle has a length of 10 cm and a width of 5 cm. What is the diagonal of the rectangle?

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What is the remainder when 5^100 is divided by 3?

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The sum of the reciprocals of two numbers is 1/4. If one number is 12, what is the other?

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A sphere has a radius of 7 cm. What is its volume?

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What is the area of a sector of a circle with radius 14 cm and central angle 90°?

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A triangle has angles 60°, 60°, and 60°. What type of triangle is it?

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If a cylinder has a radius of 7 cm and height of 10 cm, what is its volume?

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A rectangle has an area of 48 cm² and a length of 8 cm. What is its width?

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If sin(A) = 3/5 and cos(B) = 5/13, where A and B are acute angles, what is sin(A+B)?

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If a:b = 2:3 and b:c = 4:5, what is a:c?

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