Page 12 - FLIP BOOK_TASYA NATALI SIHOMBING

3. Two adjacent angles take care of each other, namely A + B = B +
C = C + D = D + A =180.

4. Diagonal jajargenjang divides the area of jajargenjang into two equal

parts, namely the area ACB = large area CAD and large area ADB =
large area CBD.

5. The diagonals bisect each other, i.e AO = CO dan BO = DO.

Perimeter and Area of Parallelogram

a. Circumference of Parallelogram
The perimeter of a parallelogram is the sum of the lengths of its four

sides. From the figure it can be obtained that the perimeter of the

parallelogram

ABCD = AB + BC +CD + DA

length AB = CD dan AD = BC,

then around ABCD = 2AB + 2BC + 2(AB + BC)

So the perimeter of the parallelogram ABCD is:

K = 2(AB + BC)
b. Area of Parallelogram

Look at Figure 1.7. The parallelogram ABCD consists of two

congruent triangles, namely ABD and CDB. So, the area of the

parallelogram ABCD is the sum of the areas ABD and CDB. If the area

of a parallelogram = L, so

L = area ABD + area CDB

= 2 x area ABD

= 2 x a x t L

L = a x t

The area of a parallelogram with a base length a unit and a height t
units is L = a x t

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