Question

Find the value of x​

Answer 1

`\large\boxed{x\approx12.94}`

Explanation:

Use cosine:

`\cosine=(adjacent)/(hypotenuse)`

We have:

`adjacent=4\\hypotenusex\\\alpha=72^o\\\\\cos72^o\approx0.309`

Substitute:

`(4)/(x)=0.309`

`(4)/(x)=(309)/(1000)` cross multiply

`309x=4000` divide both sides by 309

`x\approx12.94`