A wire is bent into a square whose area is 2025 square cm. What is the length of the wire?
Answer and explanation
Correct answer: 180 cm
Let the side of the square be s centimetres. The area formula is s², so s²=2025. Since a length is positive, s=√2025=45 cm. When the wire is bent into the boundary of the square, its length equals the square’s perimeter, 4s. Therefore the wire length is 4×45=180 cm, so option B is correct. Option A does not follow from either the side or perimeter, option C results from an incorrect multiplication, and option D is close to the area’s square-root calculation but is not the perimeter. The key steps are taking the positive square root for the side and then multiplying by four.
Frequently asked questions
What is the correct answer to this question?
180 cm
Why is this the correct answer?
Let the side of the square be s centimetres. The area formula is s², so s²=2025. Since a length is positive, s=√2025=45 cm. When the wire is bent into the boundary of the square, its length equals the square’s perimeter, 4s. Therefore the wire length is 4×45=180 cm, so option B is correct. Option A does not follow from either the side or perimeter, option C results from an incorrect multiplication, and option D is close to the area’s square-root calculation but is not the perimeter. The key steps are taking the positive square root for the side and then multiplying by four.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Word Problems and Applications.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
