In ΔDEF , DE = 12 cm, EF = 15 cm, and ∠DEF = 90°. ΔDEF is congruent to ΔXYZ. If YZ = 15 cm, then what is the length of XZ?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 3 cm

DE = 12 cm, EF = 15 cm, ∠DEF = 90°, and YZ = 15 cm
ΔDEF is congruent to ΔXYZ. So, their corresponding sides are equal.
So, EF = YZ, DE = XY, DF = XZ
In ΔDEF, DF = √(DE2 + EF2)
= √(122 + 152)
= √(144 + 225)
= √369
= 3√41 cm
XZ = DF = 3√41 cm
Therefore, the length of XZ is 3√41 cm.