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35 votes
35 votes
Oh gosh I dunno any of this-

Trigonometry

Oh gosh I dunno any of this- Trigonometry-example-1
Oh gosh I dunno any of this- Trigonometry-example-1
Oh gosh I dunno any of this- Trigonometry-example-2
User Linden
by
3.2k points

2 Answers

18 votes
18 votes
You need to use SOHCAHTOA.
Sin (opposite/hypotenuse)
Cos (adjacent/hypotenuse)
Tan (opposite/adjacent)

For the first photo, you would use
Tan( opposite/adjacent)
4/x = tan(20)
Then you just change the equation to have x on the side by itself.
(4)(tan20) = x
Then write that into the calculator.

For the second problem, you use
Sin(opposite/hypotenuse)
Sin(25)=x/10
Change the equation to have x by itself.
Sin(25)(10)=x
Then plug it into the calculator.
User Oli Folkerd
by
2.6k points
11 votes
11 votes

Answer:

Step-by-step explanation:

Triangle 1:

Problem:

Find leg
a of a right triangle if hypotenuse
c=10 and angle
\alpha =25^o.

Solution:


a
4.2262

Step-by-step explanation:

To find leg
a use formula:


\text{sin}(\alpha )=(a)/(c)

After substituting
\alpha =25^o and
c=10 we have:


sin(25^o)=(a)/(10)\\0.4226=(a)/(10)\\a=0.4226*10\\


a=4.2262

Triangle 2:

Problem:

Find leg
b of a right triangle if leg
a=4 and angle
\alpha =20^o.

Solution:


b
10.9899

Step-by-step explanation:

To find leg
b use formula:


\text{tan}(\alpha)=(a)/(b)

After substituting
\alpha =20^o and
a=4 we have:


tan(20^o)=(4)/(b)\\0.364=(4)/(b)\\b=(4)/(0.364)\\b =10.9899

User Rosaly
by
2.8k points