Applied GeometryLesson 1-5

Tools of the Trade

Objective: Learn to use geometry tools.

Definitions

Straightedge: an object used to draw a straight line.

Compass: a tool used for drawing arcs and circles.

Example

Determine whether the sides of the triangle are straight.

The sides are straight.

ExampleUse a straightedge to determine which of the three segments at upper left forms a straight line with the segment at the lower right.

Top segment.

Example

Use a compass to determine which segment is longer segment AB or segment CD.

Example

Which is longer, the segment from A to B or the segment from B to D?

Constructions

Constructions: a figure made by using a compass and straightedge.

ConstructionUse the compass to draw a circle.

Do not change the compass width

Put the point on the circle and draw a small arc on the circle.

Move the point to the arc and draw another arc.

Continue all around the circle.

Use a straightedge to connect the points in order.

Patty paper: a special kind of paper used for constructions.

Midpoint: the point located in the middle of a segment.

Homework

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