Question

In a rhombus of side $10cm$, one of the diagonals is $12cm$ long. Find the length of the second diagonal.

• A. $15cm$
• B. $16cm$
• C. $17cm$
• D. none of the above

Answer 1

The correct option is B $16cm$

REF.Image.

In $△ABO$ , applying Pythagoras

$A{B}^2=A{O}^2+O{B}^2$

${10}^2=6^2+O{B}^2$

$100-36=O{B}^2$

$OB=8$

$BD=2OB$

$=2\times 8$

$=16cm$