# Write an expression to find the area of a rectangle

Area is the number of square units inside of a shape. We typically find the area of a shape that is two dimensional like a floor, or a piece of carpet, or a piece of land. Since the area is measuring the number of square units inside of the shape, the units must be written as squared units ex: Many of the area formulas require you to know the height of the shape. The student does not recognize the trinomial as the product of two binomials. Examples of Student Work at this Level The student attempts a mathematically incorrect approach to finding the area. For example, the student: Questions Eliciting Thinking What type of figure is given?

Can you tell me the formula used to determine the area of this figure? What kind of expression is used to describe the area? What kind of expression is used to describe the length? How should these expressions be related? Instructional Implications Review the area formula for a rectangle using the symbols A for area, l for length, and w for width.

Tell the student to write this formula on his or her paper. Ask the student to identify the two parts of the area formula that are given and to write them underneath the corresponding parts of the formula. Discuss the operation that relates the length and the width in the area formula and how the length and the width can be considered factors of the area.

Since one binomial factor is given, he or she only need determine the missing binomial factor. Provide the student with more practice and experience multiplying and factoring polynomials. Guide the student to recognize factorable polynomials based on their structure.

Be sure the student understands that the factored and expanded forms of a given polynomial are equivalent, but one form might be more useful in a given problem setting. Also, be sure the student understands that not all polynomials are factorable. Examples of Student Work at this Level The student: Attempts to factor the trinomial but makes an error.

Questions Eliciting Thinking Is there a way other than division to determine the missing factor for a trinomial?

If you use a set of parentheses instead of w in your equation, could you figure out what goes in the parentheses?

Did you check your answer by multiplying the two factors? Did you get back to your original trinomial? Are your signs correct? Ask the student to check his or her factorization by finding the product of the factors and then comparing the result to the original trinomial.

Got It The student provides complete and correct responses to all components of the task. Instructional Implications Challenge the student to write an expression for the width of the rectangle if the given trinomial represented the perimeter of the rectangle.kcc1 Count to by ones and by tens.

kcc2 Count forward beginning from a given number within the known sequence (instead of having to begin at 1). kcc3 Write numbers from 0 to Represent a number of objects with a written numeral (with 0 representing a count of no objects).

kcc4a When counting objects, say the number names in the standard order, pairing each object with one and only. By dividing both the sides by 2, the equation changes to 9 = l + w, or l + w = 9.

STEP 3: Think of the possible dimensions the rectangle can have if the sum of the length and width equals 9 ashio-midori.com, it is given that area of the rectangle has to be greater than 18 sq.

## Area of a Rectangle

cm. Nov 26,  · The area of the rectangle is 35cm squared if the bottom and top of the rectangle are x+2 and the left and right side equals x, what is 1)expression of rectangle in terms of x 2)quadratic equation of the situation 3)solve the quadratic equation to find x any help would be appreciated:)Status: Resolved.

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