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The diagonal of a square is 424\sqrt{2} cm. The diagonal of another square whose area is double that of the first square, is:

Solution

✅ Correct Option: 4

The diagonal of the first square is 424\sqrt{2} cm.

For any square with side length aa, the diagonal is a2a\sqrt{2} and the area is a2a^2.


Let the side of the first square be aa.

Diagonal = a2a\sqrt{2}

42=a24\sqrt{2} = a\sqrt{2}

a=422a = \frac{4\sqrt{2}}{\sqrt{2}}

a=4a = 4 cm


Area of the first square:

Area = a2a^2

Area = (4)2(4)^2

Area = 1616 cm²


The second square has double the area:

Area of second square = 2×162 \times 16

Area of second square = 3232 cm²


Let the side of the second square be bb.

b2=32b^2 = 32

b=32b = \sqrt{32}

b=16×2b = \sqrt{16 \times 2}

b=42b = 4\sqrt{2} cm


The diagonal of the second square:

Diagonal = b2b\sqrt{2}

Diagonal = 42×24\sqrt{2} \times \sqrt{2}

Diagonal = 4×24 \times 2

Diagonal = 88 cm


The diagonal of the second square is 88 cm.

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