All angles of triangles is equal means that that triangle is equailateral triangle with side of a = 4 in.
The formula for the area of equilateral triangle is,
![A=\frac{\sqrt[]{3}a^2}{4}](https://img.qammunity.org/2023/formulas/mathematics/college/so9uylz91vkksnywlmdxxijysr70prxt0o.png)
Substitute 4 for a in the formula to determine the area of the triangle.
![\begin{gathered} A=\frac{\sqrt[]{3}}{4}\cdot(4)^2 \\ =4\sqrt[]{3} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/1madjawvioknwghfr5onbwl9n04o200wwx.png)
So area of triangle is,
![4\sqrt[]{3}](https://img.qammunity.org/2023/formulas/mathematics/college/9fx36rfoqwrrajki3g4banig36lycnp1mg.png)