This little book is intended for Elementary level students.

The Little Book of Basic Geometry

This is a collection of Little Books on various Math topics for students at Elementary level.

LITTLE BOOKS COLLECTION

Reflex Angle

An angle with a measure between 180º and 360º

Angle DEF is a reflex angle with a measure of 143°. Angle DEF is an acute angle with a measure of 37°.

Congruent Angles

You say "angle CAB is congruent to angle FED." You write .

Vertical Angles

Pairs of angles formed by intersecting lines

Vertical angles are congruent.

Adjacent Angles

You say "angle DGE is adjacent to angle EGF." You write

Graciela is an Apple Distinguished Educator, Class of 2019, Book Creator Ambassador, and Google Certified Educator from Monterrey, Mexico. She is currently in charge of the Advanced Math Program for Elementary students at Latin American School, a renowned bilingual institution and Apple Distinguished School. Her hobbies include sewing, embroidery, and crocheting. Teaching is her overall favorite activity.

Angles

An angle is formed when two rays meet at the same endpoint.

This is angle STU. Ray TS and ray TU form the sides of the angle. T, the point where the two rays meet, is the vertex of the angle.

You say "angle STU." You write .

Angles are measured in degrees. The tool used to measure angles is a protractor. Angles are classified according to their measure in degrees (º).

Acute

Acute angles measure between 0º and 90º.

Obtuse

Obtuse angles measure between 90º and 180º.

Right

Right angles measure exactly 90º.

Straight

Straight angles measure exactly 180º.

A ray is a part of a line with one endpoint, extending endlessly in only one direction.

You say "line segment AB is congruent to line segment XY." You write .

Lines that meet at a point of intersection

You say "line AB intersects line XY at point C." You write .

You say "line AB is parallel to line XY." You write .

Intersecting lines that form right angles

You say "line AB is perpendicular to line XY." You write .

Complementary Angles

Two angles with measures that have a sum of 90º

Angle DGE is adjacent to angle EGF. The measure of angle DGE is 65º. The measure of angle EGF is 25º. Together they measure 90º; therefore, they are complementary.

Supplementary Angles

Two angles with measures that have a sum of 180º

Angle DEG is adjacent to angle GEF. The measure of angle DEG is 135º. The measure of angle GEF is 45º. Together they measure 180º; therefore, they are supplementary.

<a href="bookcreator://page/wpSO2mZVS_GqmbgAre9YEA">Basic Geometric Terms</a>

<a href="bookcreator://page/2l7TgIhmQ7asT1XfgoJouQ">Lines</a>

<a href="bookcreator://page/V2LNF43cRcGo8s97FtU_7w">Angles</a>

<a href="bookcreator://page/8ApukV90T8CjB4l3d9H68Q">Angle Pairs</a>

A point is an exact location in space.

You say "point m." You write m or point m.

A line is a straight path of points that goes on forever in two directions.

You say "line ab." You write .

A line segment is a part of a line with points on each end.

You say "line segment ab." You write .

A ray is a part of a line with one endpoint, extending endlessly only in one direction.

You say "ray yz." You write .

A midpoint is a point that lies halfway between the two endpoints of a line segment.

You say "midpoint m." You write m or point m.

A plane is a flat surface extending endlessly in all directions.

You say "plane def." You write .

Name

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