1. **Problem Statement:** Calculate the area of oblique triangles using Heron's Formula given the lengths of sides $a$, $b$, and $c$. 2. **Heron's Formula:** The area $A$ of a triangle with sides $a$, $b$, and $c$ is given by: $$ A = \sqrt{s(s-a)(s-b)(s-c)} $$ where $s$ is the semi-perimeter: $$ s = \frac{a+b+c}{2} $$ 3. **Step-by-step Calculation:** - Measure or record the lengths of the three sides $a$, $b$, and $c$. - Calculate the semi-perimeter $s$ using $s = \frac{a+b+c}{2}$. - Substitute $s$, $a$, $b$, and $c$ into Heron's formula. - Compute the product $s(s-a)(s-b)(s-c)$. - Take the square root of the product to find the area $A$. 4. **Example:** Suppose a triangle has sides $a=5$, $b=6$, and $c=7$. - Calculate $s = \frac{5+6+7}{2} = 9$. - Compute the product: $9(9-5)(9-6)(9-7) = 9 \times 4 \times 3 \times 2 = 216$. - Area $A = \sqrt{216} = 6\sqrt{6} \approx 14.7$. 5. **Reflection:** Comparing estimated areas with calculated areas helps improve accuracy. Challenges include precise measurement of sides and careful substitution into the formula. This process can be repeated for each oblique triangle you find or draw to calculate their areas accurately using Heron's Formula.