Question

Which property can be justified using the ratios in triangle XYZ ?

A) cos Y = xz
B) sin Y = cos (90o - Y)
C) cos Z = sin (90o - Y)
D) tan Z = cos Ysin Z

Answer 1

The previous answer is correct. There are 2 question that look the ecaxt same. Yet are different. The answer is indeed B

Answer 2

The correct answer is B.

Determine and recall first the trigonometric functions:

Sin A = Opposite/Hypotenuse
Cos A = Adjacent/Hypotenuse
Tangent = Opposite/Adjacent

If for example we try to take an angle, for example the Y, then Y is opposite Y. The Hypotenuse will be the longer side which is going to denoted by X and the next side will be Adjacent which will be denoted by Z.

Use this test to answer:

Sin Y = Y/X

where:

Y = opposite
X = hypotenuse

Cos (90 - y) = cos (90 - 50) = cos 40

where Z = 40
we look for cos Z = Y/X

Therefore,

Sin Y = Cos (90 - Y)