## Elementary Geometry for College Students (7th Edition) Clone

$6^{2}$ = $9^{2}$ + $10^{2}$ + 2*9*10*cos α
given data a= 6,b=9 ,c= 10 using theorem 11.4.3 $a^{2}$ = $b^{2}$ + $c^{2}$ + 2bc cos α $6^{2}$ = $9^{2}$ + $10^{2}$ + 2*9*10*cos α