top of page

6.1: Intro to Triangles

6 Types of Triangles:

Based on Angles:

Right Triangle: one angle is 90 degrees

Acute Triangle: All angles are less than 90 degrees

 Obtuse Triangle: One angle is greater than 90 degrees

Based on Side Lengths:

Equilateral Triangle: all sides are equal & all angles are equal

Isosceles Triangle: 2 sides are equal & 2 angles are equal

Scalene Triangle: no sides nor angles are equal

image.png

Practice

Practice PDFs available for download: 

6.2: Intro to Angles

Example 1) How to use a protractor to measure angles

Step 1) Find the vertex and put the mid-point of the protractor there.

image.png
image.png

Step 2) Find where the angle arm reaches

Types of Angles:

Right / 90* angle

image.png

Acute Angle
(less than 90*)

Obtuse Angle
(Greater than 90*)

Reflex Angle 
Exterior Angle

Practice

Practice PDFs available for download: 

6.3: Area of Triangles

Example 1) Calculate the area of the following triangle: 

Formula:

A = 

Base x Height

2

image_edited.png

6cm

10cm

8cm

Step One: Fill in the formula with what you know; base is 8cm, height is 6cm

8cm x 6cm

2

Step Two: Complete the top part of the equation (8*6)

8cm x 6cm

= 48cm

Step Three: Complete the top part of the equation (8*6)

48cm

2

= 24cm

2

Practice

Practice PDFs available for download: 

6.4: Polygons

Polygon: a multiple-sided shape

  • a closed shape

  • sides are stright line segments

  • only 2 sides meet at a vertex

image.png

Non-Polygons: 

Regular Polygon: all sides are equal and all angles equal:

image.png
image.png

Irregular Polygon: Does not have all sides equal and all angles equal: 

image.png

Convex Polygon: Has all angles less than 180*: 

image.png

Concave Polygon: Has at least one angle greater than 180*: 

image.png

Perimeter of Polygons

Perimeter: is the distance around a polygon

P = sum of all side lengths

image_edited.jpg

8cm

6cm

Perimeter = 8 + 7 + 6
                  = 21cm

7cm

Practice

Practice PDFs available for download: 

6.5: Area of Rectangles

Area = (Length) x (width)

Formula:

Example 1) Calculate the area of the following rectangle: 

Area = x 9 

= 27m 

2

3m

9m

Here we say, "twenty-seven meters squared."
We say squared because it lets everyone know our answer is 2 dimensional (both length & width) to cover space

Practice

Practice PDFs available for download: 

6.6: Volume of Rectangular Prisms

Volume is the three dimensional space a figure takes up. 
             Calculated in cubic units

Length x Width x Height

Formula:

Example 1) Calculate the volume of the following rectangular prism: 

2

image.png

V = l x w x h

   = 11cm x 4cm x 5cm

   = 44cm  x 5cm

   = 220cm

3

Here we say, "two-hundred twenty centimeters cubed."
We say Cubed because it lets everyone know our answer is 3 dimensional (both length & width &height) to fill 3D space

Practice

Practice PDFs available for download: 

bottom of page