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

$b^{2}$ = $(5.7)^{2}$ + $(8.2)^{2}$ - 2*5.7*8.2 cos 79°
Given data a=5.7,c=8.2, β=79° Using theorem 11.4.3 In triangle ABC $b^{2}$ = $a^{2}$ + $c^{2}$ - 2ac cos β $b^{2}$ = $(5.7)^{2}$ + $(8.2)^{2}$ - 2*5.7*8.2 cos 79°