Florida B.E.S.T. MA.912.AR.2.3
The Standard
Write a linear two-variable equation for a line that is parallel or perpendicular to a given line and goes through a given point.
Florida B.E.S.T. Standards for Mathematics
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students find the slope of a given line, then choose the matching parallel slope or perpendicular slope. They use a given point to build an equation and verify it algebraically or graphically.
What Mastery Looks Like
- A student correctly finds the needed slope and substitutes the given point into point-slope form. The student rewrites the result in another form and checks that the point satisfies the equation.
Common Misconceptions
- Students may use the same slope for perpendicular lines instead of the negative reciprocal. They may change only the sign, mishandle fractions, or forget that horizontal and vertical lines are perpendicular.
How to Assess It
- Give the line y = 2x - 5 and the point (4, 1). Ask students to write both a parallel equation and a perpendicular equation through the point.
Lesson moves
Ways to Teach It
On graph paper, students draw a given line, mark a point, then use slope triangles to construct parallel and perpendicular lines.
Ask students to explain why perpendicular slopes multiply to -1, then describe the special case involving horizontal and vertical lines.
Play equation match-up with cards showing lines, points, slopes, and equations that form valid parallel or perpendicular sets.
Model two streets on a coordinate map, then write equations for a parallel service road and a perpendicular cross street through chosen locations.
Free download
Printable MA.912.AR.2.3 Worksheet
A ready-to-print activity worksheet aligned to MA.912.AR.2.3, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetKeep exploring
Related Standards
- MA.912.AR.9.1
Given a mathematical or real-world context, write and solve a system of two-variable linear equations algebraically or graphically.
- MA.912.AR.2.2
Write a linear two-variable equation to represent the relationship between two quantities from a graph, a written description or a table of values within a math...
- MA.8.AR.3.4
Given a mathematical or real-world context, graph a two-variable linear equation from a written description, a table or an equation in slope-intercept form.
- MA.912.AR.2.7
Write two-variable linear inequalities to represent relationships between quantities from a graph or a written description within a mathematical or real-world c...
Turn this exact standard into a lesson
Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.