Distance
Distance formula
Line Segment
Enduring Understandings

Calculate distance and midpoint on a coordinate plane.

Find and compare slope of lines, parallel, and perpendicular lines.

Write equations of lines.
Geometry
Unit 2A
“Coordinate Geometry”
Essential Questions:
1.
2.
How do you find the distance, midpoint, and fractional
point on a coordinate plane?
How do you find the equation of a line given two points,
a point and a slope, or two points and a parallel or
perpendicular scenario?
Academic Vocabulary
Center of dilation
Congruence
Coordinates
Definitions
Distance
Distance formula
Line Segment
Slope
Slope formula
Midpoint
Midpoint formula
Opposite reciprocals
Point-slope form, y – y1 =
m(x – x1)
Slope-intercept form, y =
mx + b
Standard form, Ax + By =C
TEKS G.1A , G.1B , G.1C , G.1D ,
G.1E , G.1F , G.1G , G.2A , G.2B , G.2C , G4D
Learning Targets
 Calculate distance on coordinate plane.
 Calculate midpoint on coordinate plane.
 Calculate equations of lines given two points, or a point and another slope described as
being parallel or perpendicular.
Teacher Management
In these lessons, we will recall from previous Algebra I lessons the equations of lines including
parallel and perpendicular scenarios. Students will need to be able to create the equation of a
line as well as compare and contrast the equations. Students will need to find the midpoint and
distance on the coordinate plane given two coordinate points.
Estimated Time
4-5 days
Materials
online textbook
teacher notes
calculator
graph paper
straight edge
ruler
protractor
Experience
Teacher led: Calculate equations of lines and verify by graphing. Find midpoints on a
coordinate plane and verify with a ruler. Calculate distance on a coordinate plane and verify
with measurements. Find perpendicular lines and verify with a protractor.
Rockwall HS Feeder Lesson Plan Template
Updated 05/14/2015
1
Literacy Strategies
Connect how the distance formula connects to the Pythagorean Theorem.
Synthesis
Students will be able to visualize, graph, and calculate linear equations, perpendicular slopes,
and parallel slopes.
Teacher Note
Some students may confuse the x- and y-coordinates, or their order, in the formulas for slope, distance, and midpoint
such as using x-values in the numerator of the slope rather than as the denominator.
Some students may confuse the order of operations in the formulas for slope, distance, and midpoint such as students
squaring the numbers before subtracting the coordinates in the distance formula rather than first subtracting the
coordinates then squaring the result.
Differentiation
Students will be able to go from graph to equations or equations to graphs of linear equations.
We will include more standard form for linear equations and relate it back to solving systems of
equations. Students will complete Challenge Problems that extend concepts of linear
equations, midpoint, and distance.
Rockwall HS Feeder Lesson Plan Template
Updated 05/14/2015
2