If , then find the values of cos θ and sin θ.

We know that,

Or

Let,

Side adjacent to angle θ =AB = 21k

The side opposite to angle θ =BC = 20k

where k is any positive integer

Firstly we have to find the value of AC.

So, we can find the value of AC with the help of Pythagoras theorem

⇒ (AB)² + (BC)² = (AC)²

⇒ (21k)² + (20k)² = (AC)²

⇒ (AC)² = 441 k² +400 k²

⇒ (AC)² = 841 k²

⇒ AC =√841 k²

⇒ AC =±29k

But side AC can’t be negative. So, AC = 29k

Now, we will find the sin θ

Side opposite to angle θ = BC = 20k

and Hypotenuse = AC = 29k

So,

Now, we know that,

Side adjacent to angle θ = AB =21k

Hypotenuse = AC =29k

So,