Question

in a rhombus of side 10cm one of the diagonal is 12 cm long .find the length of the second diagonal

Answer 1

Pythagoras theorem:
${a}^{2} + {b}^{2} = {c}^{2} \\ = > {6}^{2} + {b}^{2} = {10}^{2} \\ => {b}^{2} = {10}^{2} - {6}^{2} \\ = > {b}^{2} = 100 - 36 \\ = > {b}^{2} = 64$
$= > b = \sqrt{64} \\ = > b = 8cm$
therefore, the length of the other diagonal is 8 cm

Answer 2

by using the pythogoras theorem we can find that 8 cm is the lenght of the other diagonal