The area of the triangle is:
![\Large\displaystyle\text{$\begin{aligned}A\triangle &= (21+7√(15))/(2)\\ \\A\triangle &\approx 24.055\\ \\\end{aligned}$}](https://img.qammunity.org/2022/formulas/mathematics/high-school/l5ylh2hwhfkdinyrdpjifm67weuvtx5t4u.png)
You can easily find the area of a triangle using the formula:
![\Large\displaystyle\text{$\begin{aligned}A\triangle = (bh)/(2)\end{aligned}$}](https://img.qammunity.org/2022/formulas/mathematics/high-school/cifsze9xs4e58e3uxo6u1dtewsvyxcmecu.png)
Where h is the height of the triangle, and b the base.
Looking at the figure we can see that h = 7, but we need to discover the base, we know that the base is:
![\Large\displaystyle\text{$\begin{aligned}b = 3 + x\end{aligned}$}](https://img.qammunity.org/2022/formulas/mathematics/high-school/bidofptun977p17d86chjn3zewuu91ftyw.png)
Where:
![\Large\displaystyle\text{$\begin{aligned}8^2 &= x^2 + 7^2\\ \\x^2 &= 8^2 - 7^2 \\ \\x^2 &= 64 - 49\\ \\x^2 &= 15\\ \\x &= √(15)\end{aligned}$}](https://img.qammunity.org/2022/formulas/mathematics/high-school/b7sx4jicyehshn8xj4hg01gjdln33tfka8.png)
Therefore, our base length is:
![\Large\displaystyle\text{$\begin{aligned}b &= 3 + x\\ \\b &= 3 + √(15)\\ \\\end{aligned}$}](https://img.qammunity.org/2022/formulas/mathematics/high-school/2iks99xr7y6mcjopdwwxv69999t0c4lu94.png)
Then we can just apply the formula for the area:
![\Large\displaystyle\text{$\begin{aligned}A\triangle &= ((3+√(15))\cdot 7)/(2)\\ \\A\triangle &= (21+7√(15))/(2)\\ \\A\triangle &\approx 24.055\\ \\\end{aligned}$}](https://img.qammunity.org/2022/formulas/mathematics/high-school/opu6oa7hdk20nkwmzgghfnyb6okz84eze2.png)
I hope you liked it
Any doubt? Write it in the comments and I'll help you