영어로 배우는 초등학교 5학년 수학 - 도형의 넓이 / Finding the Area of Figures [ 영문 ]

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  영어로  배우는 초등학교  5 학년 수학  -  도형의 넓이 구하기

     Finding  the Area  of  Figures       

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  Watch Video on Area of a Trapezoid - Geometry Help  

  ■  The Area of Figures

       ☆  Trapezoid

  In a trapezoid, the parallel two sides are called Base. 
According to their location, they are called  Upper Base  or  Lower Base.
And the distance between two bases is called Height.

  ( Area of a Trapezoid ) 

=  Area of a Parallelogram ÷ 2

= ( Base )  × ( Height )  ÷ 2

= { ( Upper Base ) + ( Lower Base ) }  ×  ( Height ) ÷ 2

  ◈  The Area of a Rhombus    

       ☜    Video Tutor      

Watch Video on Area of a Rhombus - Geometry Help

 ( Area of a Rhombus )

= ( Area of a Rectangle )  ÷ 2

= ( Length ) X ( Width ) ÷ 2

= ( length of a diagonal )  ×  ( length of the other diagonal ) ÷ 2

                       Practice   Quiz                      

1.  Find the area of shaded region.   

 Solution  :   Shaded region is the half of the total rectangle area.

                                        ( 20 × 10 ) ÷ 2 = 100                   

Answer    :    100

2.  Find the area of the trapezoid.  

Solution  :   ( 4 + 2 ) × 5 ÷ 2 = 15  ( cm^2 )   

Answer  :  15  ( cm^2 )

 3.  Find the area of the rhombus.  

Solution  :   Area of the rhombus = 8 × 7 ÷ 2 = 28 (cm^2)

Answer   :   28 

 
4.  The area of the following rhombus is 90 cm².   Fill in the blank. 

                           

 Solution        9 × □ ÷ 2 = 90    ⇒   □ = 20 (cm)