Chapter 13, Trigonometric Ratios and Functions - 13.6 Apply the Law of Cosines - 13.6 Exercises - Skill Practice - Page 892: 32

$$A=4\sqrt{3441}$$

By Heron's Formula, we know: $$A=\sqrt{s(s-a)(s-b)(s-c)}$$ Where: $$s=\frac{a+b+c}{2}$$ Thus, we find: $$s=\frac{38+25+61}{2}=62 \\ A=\sqrt{62\left(62-38\right)\left(62-25\right)\left(62-61\right)} \\ A=4\sqrt{3441}$$