Question

Trigonometry I need to find the perimeter of the triangle​

Answer 1

so, the bottom-left angle is 60°, and the bottom-right angle is 60° as well, that simply means the angle up above is also 60°, meaning, this is an equilateral triangle.

`\bf \textit{height of an equilateral triangle}\\\\ h=\cfrac{s√(3)}{2}~~ \begin{cases} s=side's\\ \qquad length\\[-0.5em] \hrulefill\\ h=4√(15) \end{cases}\implies 4√(15)=\cfrac{s√(3)}{2}\implies 8√(15)=s√(3) \\\\\\ \cfrac{8√(15)}{√(3)}=s\implies \cfrac{8√(3\cdot 5)}{√(3)}=s\implies \cfrac{8\underline{√(3)}\cdot √(5)}{\underline{√(3)}}=s\implies 8√(5)=s`