Answer:
The Figure for Right triangle is below,
Therefore , 15 unit length represents BC.
Step-by-step explanation:
Given:
Consider a right triangle ABC, Such that

To Find:
BC = ?
Solution:
In Right Angle Triangle ABC, Cosine and Tangent identity


BUT,
....Given
On Comparing,
Adjacent side to angle A = AB = 15
Opposite side to angle A = BC = 8
Hypotenuse = AC =17
Also Pythagoras theorem is Satisfies,



The Figure for Right triangle is below,
Therefore , 15 unit length represents BC.