An iron tank is constructed in the form of an isosceles trapezoid. Each base angle measures 105°, the length of the base is 10 feet, and each of the nonparallel sides is 12 feet long. Determine the length of a diagonal brace to the nearest whole number.

Question

anonymous · Answer

attachment

triciaal · Answer

c^2 = a^2 + b^2 - 2 a b Cos C
c^2 =  12^2 + 10^2 - 2*12*10* Cos 105
= 144 + 100 - 240*-0.26 = 244 + 62.1 = 306.1 
c = rt 306.1 = 17.5   rounded to 18

not certain 
do you have answer choices ?

anonymous · Answer

yes they are 
10 ft
13 ft
18 ft
24 ft

triciaal · Answer

so I guess correct  18

triciaal · Answer

used the cosine rule to find the side of the triangle  the largest side is opposite the largest angle here 105 and here the side of the triangle is the length of the diagonal requested

anonymous · Answer

okay thank you so much @triciaal !!

triciaal · Answer

welcome