options: Modeling: students learn to choose and use appropriate mathematics and statistics to analyze real-world empirical situations, improve decisions, and report on their conclusions and the reasoning behind them.

Number & Operations in Base Ten: students learn to work with the base-ten system and build place value understanding.

Geometry: students learn to classify geometric figures by their properties, and understand and compare the relationships between them. Students develop and use formulas to compute lengths, areas, and volumes, and they use transformations to generate new shapes and compare existing ones. Geometry can be studied with and without coordinates.

Number Systems and Quantity: students learn to understand the complex number system and reason quantitatively.

Ratios & Proportional Relationships: students learn to recognize, describe, represent, and reason with ratios, rates, proportional relationships, and percent.

Functions: students learn to define, use, and evaluate functions to model relationships between quantities.

Operations & Algebra: students learn to solve problems using algebraic thinking and operations such as addition, subtraction, multiplication, and division. They may learn to identify and explain arithmetic patterns, evaluate or manipulate numerical expressions, and reason with equations and inequalities.

Number & Operations - Fractions: students learn to understand fractions as numbers and may work with them using addition, subtraction, multiplication, and division.

Counting & Cardinality: students learn to know number names and the count sequence, count to tell the number of objects, and compare numbers.

Measurement & Data: students learn to work with data and measure attributes such as time, money, length, area, and volume. They may learn to compare measurements to operations and convert between different units of measure.

Statistics & Probability: students learn to analyze and produce data distributions, and build understanding of univariate and bivariate data. They learn to interpret data, make statistical inferences, justify conclusions, understand rules of probability, and use probability to make decisions.
problem_activity: Warm-up
The purpose of this warm-up is to ensure students understand that
they can infer the coordinates of a point based on knowing the coordinates of points on the same horizontal and vertical lines;
the length of a horizontal or vertical line segment can be determined based on the coordinates of its endpoints. Each of these is important background knowledge for this lesson.
Launch
Give students 2 minutes of quiet think time. Ask them to share their reasoning with a partner followed by a whole-class discussion.
Student Facing
[IMG]
Find each of the following and explain your reasoning:
The length of segment
\(BE\)
.
The coordinates of
\(E\)
.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Anticipated Misconceptions
In order to find the length of segment
\(BE\)
, it is first necessary to find the lengths of
\(CD\)
,
\(AC\)
, and
\(AB\)
, and reason about side lengths in similar triangles. If students have trouble getting started, scaffold the work by suggesting they first find any
other
segment lengths in the diagram that they can find.
Activity Synthesis
There are three important things students should understand or recall as a result of working on the warm-up:
Points on the same vertical line have the same
\(x\)
-coordinate and points on the same horizontal line have the same
\(y\)
-coordinate.
In order to find the length of a vertical segment, you can subtract the
\(y\)
-coordinates of its endpoints.
The side lengths of triangle
\(ACD\)
are the same as the side lengths of the similar triangle
\(ABE\)
multiplied by the scale factor
\(AC \div AB\)
.
Display the image from the task. For each question, invite a student to share their reasoning. The displayed image should be used as a tool for gesturing. For example, if you start at the origin and want to navigate to point
\(D\)
, you would move 4 units to the right. You move the same distance to the right to navigate from the origin to
\(C\)
. Therefore,
\(C\)
must have the same
\(x\)
-coordinate as
\(D\)
.


correct_option_index: 2