## Elementary Geometry for College Students (5th Edition)

$c^{2}$ = $(7.9)^{2}$ + $(5.2)^{2}$ + 2*5.2*7.9 cos 83°
Given data a=5.2,b=7.9, γ=83° Using theorem 11.4.3 $c^{2}$ = $b^{2}$ + $a^{2}$ + 2ab cos γ $c^{2}$ = $(7.9)^{2}$ + $(5.2)^{2}$ + 2*5.2*7.9 cos 83° $c^{2}$ = $(7.9)^{2}$ + $(5.2)^{2}$ + 2*5.2*7.9 cos 83°