37. If the sum of the diagonals of a rectangle is 26 centimeters and one of its sides is 5 centimeters, find the sum of the lengths of the other three sides of the rectangle.



Answer :

Sure! Let's solve this step-by-step.

1. Understanding the Problem:
- The sum of the diagonals of the rectangle is given as 26 cm.
- One of the sides of the rectangle is given as 5 cm.
- We need to find the sum of the lengths of the other three sides of the rectangle.

2. Find the Length of one diagonal:
Since the sum of the diagonals is 26 cm and the diagonals of a rectangle are equal in length, each diagonal would be:
[tex]\[ \text{Length of one diagonal} = \frac{26}{2} = 13 \text{ cm} \][/tex]

3. Using the Pythagorean theorem:
The diagonals of a rectangle divide it into two right-angled triangles. Using the Pythagorean theorem in one of these triangles, we can find the length of the other side. Let's denote the unknown side as [tex]\( b \)[/tex].

The relationship is given by:
[tex]\[ \text{Diagonal}^2 = \text{side}_a^2 + \text{side}_b^2 \][/tex]
Substituting the known values:
[tex]\[ 13^2 = 5^2 + b^2 \][/tex]
[tex]\[ 169 = 25 + b^2 \][/tex]
Now, solving for [tex]\( b \)[/tex]:
[tex]\[ b^2 = 169 - 25 = 144 \][/tex]
[tex]\[ b = \sqrt{144} = 12 \text{ cm} \][/tex]

4. Calculate the sum of the lengths of the other three sides:
- Sum of the other three sides of the rectangle includes:
- The given side [tex]\( a = 5 \text{ cm} \)[/tex]
- The unknown side [tex]\( b = 12 \text{ cm} \)[/tex]
- Another instance of side [tex]\( a = 5 \text{ cm} \)[/tex] and side [tex]\( b = 12 \text{ cm} \)[/tex]

So, the sum is:
[tex]\[ \text{Sum} = \text{side}_a + \text{side}_b + \text{side}_b = 5 + 5 + 12 + 12 = 34 \text{ cm} \][/tex]

Therefore, the sum of the lengths of the other three sides of the rectangle is 34 cm.