**Elementary School Number Sense Lesson 16: Parallelograms**

There are several concepts on number sense tests dealing with 4-sided polygons:

**Rectangle**,

**Squares**,

**Rhombus**,

**Trapezoid**, and now Parallelogram. This concept appeared

**4 times**this year, with a median placement at

**question # 72**.

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**Number Dojo Level: 158**

A parallelogram is a quadrilateral with:

- Two sets of equal & parallel sides (opposite each other), and
- Two sets of equal angles (opposite each other).

There are two important formulas to know:

- The
**area**of a parallelogram is calculated by multiplying its**base**times its**height**. (A = Bh) - The
**perimeter**is twice the sum of 2 adjacent sides (the different lengths). P = 2(L + W)

**Example 1: The area of a parallelogram with base 22 and height 9 is ___**

- A = Bh
- 22 x 9 = 11 x 18 (
**Double/Half**) =**198**

**Example 2: The area of a parallelogram with base 6 and height 5 is ___**

- A = Bh
- 6 x 5 =
**30**

**Example 3: The height of a parallelogram with area 15 square inches and base 2.5 inches is ___ inches**

- A = Bh, so h = A/B
- 15/2.5 = 30/5 (
**DivDouble1st**) =**6**

**Example 4: The base of a parallelogram with area 104 sq cm and height 13 cm is ___ cm**

- A = Bh, so B = A/h
- 104/13 =
**8**

**Example 5: The perimeter of a parallelogram with adjacent sides being 6 and 8 is ___**

- P = 2(L + W)
- P = 2(6 + 8) = 2(14) =
**28**

**Example 6: If two of the side lengths of a parallelogram are 12 and 17, then the perimeter is ___**

- P = 2(L + W)
- P = 2(12 + 17) = 2(29) =
**58**

**Up Next for Elementary School: Round**