Christopher Columbus

Christopher Columbus
Born: October 31, 1451, Genoa
Died: May 20, 1506, Valladolid
Full name: Cristoforo Colombo

Henry Hudson

Henry Hudson was an English sea explorer and navigator in the early 17th century. Hudson made two attempts on behalf of English merchants to find a prospective Northwest Passage to Cathay via a route above the Arctic Circle.

Born: 1565, England
Died: 1611, Hudson Bay
Full name: Henry Hudson
Nationality: English, British

Did you finish Social Studies packet. DUE FRIDAY 12-7!!!!!

Polygons

Properties of Regular Polygons

Polygon

A polygon is a plane shape (two-dimensional) with straight sides. Examples include triangles, quadrilaterals, pentagons, hexagons and so on.

Regular

A "Regular Polygon" has: all sides equal and all angles equal. Otherwise it is irregular.

Regular Pentagon   Irregular Pentagon

Here we will be looking at Regular Polygons only.

Properties

So what can we know about regular polygons? First of all, we can work out angles.

Exterior Angle The Exterior Angle is the angle between any side of a shape, and a line extended from the next side.

All the Exterior Angles of a polygon add up to 360°, so: Each exterior angle must be 360°/n (where n is the number of sides) Press play button to see.

Example: What is the exterior angle of a regular octagon?

An octagon has 8 sides, so:

Exterior angle = 360°/n = 360°/8 = 45°

Adjacent Angles

Two angles are Adjacent if they have a common side and a common vertex (corner point) and don't overlap.

	Angle ABC is adjacent to angle CBD Because: they have a common side (line CB) they have a common vertex (point B)

What Is and Isn't an Adjacent Angle

These ARE Adjacent Angles they share a vertex and a side		NOT Adjacent Angles they only share a vertex, not a side		NOT Adjacent Angles they only share a side, not a vertex

Don't Overlap!

ALSO the angles must not overlap.

Math Test 1

Unit 3 Math Test on 12-6-12.

You should know that:

Type of Angle	Description
Acute Angle	an angle that is less than 90°
Right Angle	an angle that is 90° exactly
Obtuse Angle	an angle that is greater than 90° but less than 180°
Straight Angle	an angle that is 180° exactly
Reflex Angle	an angle that is greater than 180°

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