CPhill

Since many people do not like to have any sort of radical in a denominator, we can get rid of this by multiplying the numerator and denominator by 1-√3....so we have

-4 / (1+√3) *  (1-√3) / (1-√3) 

The denominator of the resulting fraction becomes (1 -3) = -2

So we have ...   (-4)*(1-√3) /( -2) =  2 (1-√3)

Note how this procedure leaves us with no fraction at all......however, we still have a "nasty" radical hanging around....!!!

Huh?? On No. 10, all I see is a problem about congruent triangles....I don't see any "A B C" numbers ..... am I missing something??

CBA ≅ DBE    by Angle-Angle-Side

I think I know what you mean....the base subtends an arc of 116°......and an inscribed angle measures 1/2 of the arc it intercepts..so "a" = 58°

LOL!!!!

Actually...the only "poly" I'm familiar with is when my bird says, " 'Poly' want a cracker."

You can find volumes and surface areas for all types of objects here:

So......A = 30°

Sin 30°  =  1/2

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