Question

find the perimeter of rectangle whose whose whose length is 40 cm and diagonal is 41 CM​

Answer 1

Answer:

• The perimeter of a rectangle = 98 cm

Step-by-step explanation:

Given that:

• The length of of a rectangle = 40 cm
• Length of diagonal = 41 cm

To Find:

• The perimeter of a rectangle.

Formula used:

• Perimeter of a rectangle = 2(Length + Breadth)

First finding the breadth:

• By using pythagoras theorem.

→ (Diagonal)² = (Length)² + (Breadth)²

• Substituting the values.

→ (41 cm)² = (40 cm)² + (Breadth)²

→ 1681 cm² = 1600 cm² + (Breadth)²

→ (Breadth)² = (1681 - 1600) cm²

→ (Breadth)² = 81 cm²

→ Breadth = √(81 cm²)

→ Breadth = 9 cm

Now finding the perimeter:

→ Perimeter = 2(Length + Breadth)

• Substituting the values.

→ Perimeter = 2(40 cm + 9 cm)

→ Perimeter = 2 × 49 cm

→ Perimeter = 98 cm

Answer 2

Answer:

Perimeter = 98cm

Step-by-step explanation:

Question:

Find the perimeter of rectangle whose whose whose length is 40 cm and diagonal is 41 cm

Given:

• Length of rectangle = 40 cm
• Diagonal = 41 cm

To find:

• Breadth of rectangle
• Perimeter of rectangle

Formulas used:

• b = $\tt{\sqrt{d {}^{2} - l {}^{2}}}$

• $\underline{\boxed{\tt{\pink{p \: = 2(l+b) }}}}$

Solution:

Apply the formulas:

• b = $\tt{\sqrt{41 {}^{2} - 40 {}^{2}}}$

• b = $\tt{\sqrt{1681 - 1600}}$

• b = $\tt{\sqrt{81}}$

• b = $\tt{9cm}$

So, breadth of rectangle= 9cm

p = 2(l+b)

• p = 2(40+9)

• p = 2(49)

• p = 98cm

Hence, Perimeter = 98cm