A rhombus has side lengths of 25. What could be the lengths of the diagonals?

A. 22 and 40
B. 26 and 36
C. 26 and 48
D. 30 and 40

1 answer

To determine the possible lengths of the diagonals of a rhombus given that each side measures 25, we can use the properties of a rhombus. In a rhombus, the diagonals bisect each other at right angles. Therefore, let's denote the lengths of the diagonals as \(d_1\) and \(d_2\).

From the properties of the rhombus, we can derive that the half-diagonals form right triangles with the sides. Each half-length of the diagonals is given by \( \frac{d_1}{2} \) and \( \frac{d_2}{2} \). According to the Pythagorean theorem:

\[ \left(\frac{d_1}{2}\right)^2 + \left(\frac{d_2}{2}\right)^2 = 25^2 \]

This simplifies to:

\[ \frac{d_1^2}{4} + \frac{d_2^2}{4} = 625 \]

Multiplying through by 4, we get:

\[ d_1^2 + d_2^2 = 2500 \]

Now, we can evaluate each option provided:

A. \(d_1 = 22, d_2 = 40\)

\[ 22^2 + 40^2 = 484 + 1600 = 2084 \quad (\text{Not equal to } 2500) \]

B. \(d_1 = 26, d_2 = 36\)

\[ 26^2 + 36^2 = 676 + 1296 = 1972 \quad (\text{Not equal to } 2500) \]

C. \(d_1 = 26, d_2 = 48\)

\[ 26^2 + 48^2 = 676 + 2304 = 2980 \quad (\text{Not equal to } 2500) \]

D. \(d_1 = 30, d_2 = 40\)

\[ 30^2 + 40^2 = 900 + 1600 = 2500 \quad (\text{Equal to } 2500) \]

Only option D satisfies the equation \(d_1^2 + d_2^2 = 2500\). Thus, the lengths of the diagonals could be:

D. 30 and 40.