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If ∆XYZ ~ ∆BAC find sin A, cos A and tan A

Please explain!

If ∆XYZ ~ ∆BAC find sin A, cos A and tan A Please explain!-example-1

2 Answers

4 votes
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If ∆XYZ ~ ∆BAC find sin A, cos A and tan A Please explain!-example-1
User Ashar Syed
by
5.1k points
6 votes

Answer:

Sin A = 2sqrt(5)/5

Cos A = sqrt(5)/5

Tan A = 2

Explanation:

If the triangles are similar, the sin, cos and tan values will be the same on either triangle.

So Sin A = Sin Y

Sin Y = opposite / hypotenuse

= 6/3 sqrt(5)

We do not leave sqrt's in the denominator. Multiply by sqrt(5)/sqrt(5)

6 sqrt(5) / 3 sqrt(5)*sqrt(5)

6sqrt(5) / 15

2sqrt(5)/5

The third side of the triangle is found by the Pythagorean theorem

YZ^2 +6^2 = (3sqrt(5))^2

yz^2 +36 = 9*5

YZ^2 +36 = 45

YZ^2 +36-36 = 45-36

YZ^2 = 9

Take the square root

YZ =3

Cos Y = adjacent / hypotenuse

= 3/3sqrt(5)

= 1/sqrt(5)

We do not leave sqrt's in the denominator. Multiply by sqrt(5)/sqrt(5)

= sqrt(5)/sqrt(5)*sqrt(5)

sqrt(5)/5

Tan Y = oppositie/adjancent

=6/ 3

=2

Since They are the same for Y or A

Sin A = 2sqrt(5)/5

Cos A = sqrt(5)/5

Tan A = 2

User Mozey
by
6.1k points