Question in picture.
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= 0.6
Using Pythagoras theorrem
Base² + height ² = Hypotenuse²
Thus;
Base² = 15² - 12²
= 81
Base = √81 = 9
But; cosine = adjacent/hypotenuse
Hence; cos θ = 9/15
= 0.6
The right choice is (A) 0.60
As we know
CosФ = base / hypotenuse
We dont have base so we can find it by Pythagorean Theorem
Hypotenuse² = Base² + height ²
Arranging for Base we get
Base² = 15² - 12²
Base² = 81
Taking square root on both sides
Base = √81 = 9
Now put this in the formula of cosФ
CosФ = base / hypotenuse
cos θ = 9/15
θ = cos⁻¹ (9/5)
which is 0.06