ill get help @Keigh2015 @Mehek14
This is a classic example of the cosine rule Do you know the cosine rule?
no - htat is the Pythagoras rule cosine rule is a^2 = b^2 + c^2 - 2bc cos(A) do oyu recognise that?
yes i do
so 1.3^2 is equal to x^2 + 1.1^2
OK - well you need to just get a handle on the meaning of a,b c and angleA and refer them to the values in your diagram you are directly given in the drawing the equivalent of b, c and angleA so oyu can use the formula as I gave it to solve for a (which is the side AC in your diagram)
|dw:1437053951148:dw| put the values from your drawing into the diagram above then use cosine formula to solve for a
hte formula you gave me makes no sense with te triangle
That's why I said you need to understand the formula and what a,b,c and A mean However my diagram above gives you more guidance replace the values in your drawing with the letters in my diagram - THEN it corresponds with the formula.
is as far as i got... - 2bc doesnt make any sense
so when I asked if oyu recognised the cosine rule you said yes but it seems oyu don't You need to review oyur notes or study "Cosine Rule" and understand it , before you can answer this question. This is evidently the topic oyu are studying - so refer to your class , or your text, or search online - but you must understand it before you can answer this
will you attempt to explain?
I'm afraid I don't have time to go back to the beginning the question is a classic example of the 'cosine rule' (sometimes called 'law of cosine' and allows you to solve a triangle when you know 2 sides and the include angle (as in oyur drawing). The only slightly tricky bit is the 'nomenclature' i.e. which side is a,b ,c and which angle is A look here for an explanation https://en.wikipedia.org/wiki/Law_of_cosines with the cosine rule and the sine rule you can solve nearly all problems about triangles