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Elenna [48]
3 years ago
6

IS ANYONE GOOD IN LAW OF COSINES..If so ill give brainlest​

Mathematics
1 answer:
marysya [2.9K]3 years ago
6 0

Answer:

X=70.5^o

Step-by-step explanation:

we know that

The formula of the law of cosines is equal to

c^2=a^2+b^2-2(a)(b)cos(C)

where

a, b and c are sides. C is the angle opposite side c

In this context

The formula to calculate the measure of angle X is equal to

YZ^2=XZ^2+XY^2-2(XZ)(XY)cos(X)

substitute the given values

22^2=20^2+18^2-2(20)(18)cos(X)

solve for cos(X)

484=400+324-(720)cos(X)

484=724-(720)cos(X)

(720)cos(X)=724-484

(720)cos(X)=240

cos(X)=240/720

X=cos^{-1}(240/720)=70.5^o

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