Geometry Exploration

Geometry Exploration

by Althia McKay

​Let's Talk About Types of Triangles

​Can you state some types of triangle?

​For example: Right Triangle

​

​Your Turn:

Multiple Choice

Which triangle has 3 equal sides?

• Right Triangle

• Isosceles Triangle

• Equilateral Triangle

Poll

Select possible set of dimensions for an isosceles triangle

• 5 cm, 7 cm, 10 cm

• 4 cm, 4 cm, 10 cm

• 3 cm, 4 cm, 5 cm

Multiple Choice

How do you find the AREA of a TRIANGLE?

• Length x Width
• Base x Height divided by 2
• 1/3 (Length x width)
• Base x Height

Multiple Choice

• 108 cm
• 540 cm
• 108 cm²
• 54 cm²

Multiple Choice

• 17 units²
• 20 units²
• 10 units²
• 16 units²

Multiple Choice

What is the formula for the area of a rectangle?

• Length x Width

• Length x Length

• Width x Width

Multiple Choice

When calculating the area of a square, you only need to know the measurement of 1 side because they are all the same.

• True

• False

Multiple Choice

Find the area of this square

• 49 inches

• 49 units

• 14 units²

• 49 units²

​Perimeter of a Circle

​Perimeter of a circle is also called the circumference of the circle.

​

​To find the perimeter for regular 2D shapes like triangles, squares and rectangle, we just add all the dimensions.

​

​Perimeter of Circle condt.

​To calculate the perimeter of a circle...

Multiple Choice

Is the red line a radius or diameter of the circle?

• Radius
• Diameter

Multiple Choice

If my diameter is 19 inches, what is my radius?

• 38 inches
• 9.5 inches
• 59.66 inches
• 119.32 inches

Multiple Choice

What is the circumference of this circle ?

• 3.14 cm 
• 37.68 cm
• 24 cm
• 68.4 cm

Multiple Choice

Find the circumference (to the nearest whole number)

• 88 in
• 44 in
• 116 square in
• None of the above

​Area of a Circle

​To find the area of a circle we need pi and the radius of the circle. We put a little more on it though... What is the formula for the area of a circle?

Multiple Choice

What is the formula for area of a circle?

• A = pi x D
• A = 2pi x r
• A = pi x r²

• A = pi x D2

​Perimeter of Compound Shapes

What is a Compound Shape?

​

​

​

​To find the perimeter of a compound shape we need the measurement of all the______.

​Can you find the perimeter of this Compound Shape?

​ km

​Can you Calculate the Perimeter of this Compound Shape?

​ad

​How do we find unknown sides?

​ll

Multiple Choice

Find the perimeter of the given shape

• 19 ft

• 22 ft

• 16 ft

• 21 ft

Multiple Choice

What is the perimeter of the compound shape?

• 20 cm

• 4 cm

• 30 cm

• 19 cm

​Area of Compound Shape

​ew

Multiple Choice

Find the missing yellow length

• 2 cm

• 6 cm

• 9 cm

• 4 cm

Fill in the Blanks

Multiple Choice

The area of rectangle B is ?

• 5 cm x 12 cm

• 5 cm x 11 cm

• 12 cm x 5 cm

• 8 cm x 5 cm

Multiple Choice

Find the area of the following shape

• 7920cm²

• 178cm²

• 186cm²

• 213cm²

Multiple Choice

What is the area of the composite figure?

• 80 cm²

• 16 cm²

• 96 cm²

• 32 cm²

Multiple Choice

Find the area of the polygon.

• 14 in²
• 68 in²
• 36 in²
• 24 in²

​Area of a Compound Shape