The ones with a square in a picture is a 90 degree angle the rest are a 180
Um.... 368 369 370 371 372 372 374 375 376 377 378 379 etc
Answer: 2√2 - 3Explanation:The expession written properly is:

To rationalize that kind of expressions, this is to eliminate the radicals on the denominator you use conjugate rationalization.
That is, you have to multiply both numerator and denominator times the conjugate of the denominator.
The conjugate of √3+√6 is √3 - √6, so let's do it:

To help you with the solution of that expression, I will show each part.
1) Numerator: (√3 - √6) . (√3 - √6) = (√3 - √6)^2 = (√3)^2 - 2√3√6 + (√6)^2 =
= 3 - 2√18 + 6 = 9 - 6√2.
2) Denominator: (√3 + √6).(√3 - √6) = (√3)^2 - (√6)^2 = 3 - 6 = - 3
3) Then the resulting expression is:
9 - 6√2
-----------
-3
Which can be further simplified, dividing by - 3
-3 + 2√2
Answer: 2√2 - 3
Set up proportion 170/180=x/1 than cross multiply 170x=180 divide both sides by 170 answer 0.944 so 94% remains