Question

The diagram shows a right angled triangle. 11cm 8cm and x degrees. Find the size of angle x. Give your answer correct to 1 decimal place.​

Answer 1

Given:

• hyp= 11 cm
• adj= 8 cm

Note that:

• hyp: Hypotenuse
• adj: Adjacent

To find:

The size of the unknown angle "x"

Solution:

We'll have to check which one is appropriate from SOHCAHTOA.

In this question hypotenuse and adjacent is given so, we'll have to use cos.

`\large\boxed{Formula: cos \: (A)= (adj)/(hyp)}`

Let's solve!

Let's substitute the values according to the formula.

`cos \: x= (8)/(11)`

We'll have to use cos inverse.

`x= {cos}^(-1)( (8)/(11) )`

`x= 43.34175823`

Now we'll have to round off to 1 decimal place.

The value in hundredths place is less than 5 so we won't have to round up.

So, the final answer is:

`\large\boxed{x= 43.3°}`

Therefore, the size of the unknown angle "x" is 43.3°