Examples with solutions for Area of a Trapezoid: Verifying whether or not the formula is applicable

Exercise #1

Calculate the area of the trapezoid.

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Video Solution

Step-by-Step Solution

To find the area of the trapezoid, we would ideally use the formula:

A=12×(b1+b2)×h A = \frac{1}{2} \times (b_1 + b_2) \times h

where b1b_1 and b2b_2 are the lengths of the two parallel sides and hh is the height. However, the given information is incomplete for these purposes.

The numbers provided (66, 77, 1212, and 55) do not clearly designate which are the bases and what is the height. Without this information, the dimensions cannot be definitively identified, making it impossible to calculate the area accurately.

Thus, the problem, based on the given diagram and information, cannot be solved for the area of the trapezoid.

Therefore, the correct answer is: It cannot be calculated.

Answer

It cannot be calculated.

Exercise #2

Calculate the area of the trapezoid.

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Video Solution

Step-by-Step Solution

We use the formula (base+base) multiplied by the height and divided by 2.

Note that we are only provided with one base and it is not possible to determine the size of the other base.

Therefore, the area cannot be calculated.

Answer

Cannot be calculated.

Exercise #3

The area of the trapezoid in the diagram is 9 cm².

Calculate the length of the line marked in red.

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Video Solution

Step-by-Step Solution

For this trapezoid problem, the necessary dimensions to determine the length of the red line are insufficient due to missing base lengths. Since no complete base information or relevant assumptions are available to resolve this, we cannot calculate the red line length.

Therefore, the problem concludes as per option choice: It is impossible to calculate.

Answer

It is impossible to calculate.

Exercise #4

ABCD is a trapezoid.

AB = 4 cm

DC = 7 cm

BK = 6 cm

Can the trapezoidal area formula be applied? If so, apply it and calculate.

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Video Solution

Step-by-Step Solution

The formula for the area of a trapezoid is:

S=(AB+DC)×h2 S=\frac{(AB+DC)\times h}{2}

Since we are given AB and DC but not the height, we cannot calculate the area of the trapezoid.

Answer

It cannot be applied.

Exercise #5

ABCD is an isosceles trapezoid.

AB = 5

DC = 7

DB = 9

Is it possible to apply the trapezoidal area formula, and if so, then what is the area of the trapezoid?

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Video Solution

Answer

It can be applied: 185 18\cdot\sqrt{5} cm²