Area of polygons (advanced)

Area of polygons
(Advanced :)

Something you already known in new

Fomulas for calculating the area of polygon

Multiple Choice

Which of the following horizontal form (橫式) can calculate the area of the Trapezoid.

• ( 11 x 19 ) /2

• ( 11 + 19 ) x 15 /2

• ( 19 + 11 ) x 17 /2

• ( 15 + 17 ) x 19 /2

How about the irregular polygons?

Filling up the missing part (and subtract it) to make it easier to calculate

Filling method

Cut the irregular shape polygon in to regular form, to make it easier to calculate

Dissecting method

​2 ways to solve the question

Fill in the Blanks

Calculate the size of the shaded area. (Include the proper units, m2)

Multiple Choice

Calculate the size of the shaded area. (Include the proper units)

• 165cm square

• 200cm square

• 205cm square

• 225cm square

Fill in the Blanks

A podium is made by an square and an Isosceles trapezoid (等腰梯形), the Perimeter of the podium is 32m. Calculate the area of the podium. (Include the proper units, m2)

(Hints: find the length of the square first)

Poll

Is it correct?

• YES

• NO

Poll

Is it correct?

• YES

• NO

BOSS mode

Draw

[Calculate the area of this figure]

Group A dissecting the figure into 2 triangles.

Group B dissecting the figure into 2 trapezoids.

What's wrong with these two calculations?