Calculate X in the Parallelogram: Step-by-Step to Find Height BE

Question

The area of the parallelogram below is 56.

BE is its height.

Calculate x.

x+5x+5x+5x-5x-5x-5AAADDDCCCBBBEEE

Video Solution

Solution Steps

00:00 Find X
00:03 In a parallelogram with equal opposite sides
00:12 We'll use the formula for calculating the area of a parallelogram (side times height)
00:20 We'll substitute the side values according to the given data
00:28 We'll substitute the area value according to the given data and solve for X
00:39 We'll use the shortened multiplication formulas to expand the brackets
00:54 Calculate 5 squared
01:03 Isolate X
01:14 Extract the root to find possible solutions for X
01:18 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll calculate x x using the provided expressions for the base and height of the parallelogram.

Given the area of the parallelogram:

A=(base)×(height) A = (\text{base}) \times (\text{height})

In our case, the base is x+5 x + 5 , and the height is x5 x - 5 . Therefore, we have:

(x+5)(x5)=56(x + 5)(x - 5) = 56

Recognizing this as a difference of squares, we write:

x225=56x^2 - 25 = 56

Add 25 to both sides to isolate x2 x^2 :

x2=81x^2 = 81

Take the square root of both sides:

x=±9x = \pm 9

Since both dimensions of a parallelogram must be positive in practical applications, we take x=9 x = 9 .

Therefore, the correct solution is x=9 x = 9 .

Answer

9 9