Answer:
DF is 15.7 unit
Explanation:
Given,
In triangle DEF,
m∠E = 90°, m∠F = 34° and EF = 13,
We have to find the measure of side DF.
By the property of a triangle,
m∠E + m∠F + m∠D = 180°
⇒ 90° + 34° + m∠D = 180°
⇒ m∠D = 180° - 124° = 56°
By the law of sines,

( By cross multiplication )

By substituting values,
