Answer:
[tex](2x^2+16x+32)\ \text{sq. inches}[/tex]
Step-by-step explanation:
b = h = Base = Height of triangle = [tex](x+4)\ \text{inches}[/tex]
Area of one triangle
[tex]A=\dfrac{1}{2}bh=\dfrac{1}{2}(x+4)(x+4)[/tex]
There are 4 colored triangles so total area of the triangles is
[tex]4A=4\times \dfrac{1}{2}(x+4)(x+4)\\\Rightarrow 4A=2(x+4)^2\\\Rightarrow 4A=2(x^2+8x+16)\\\Rightarrow 4A=2x^2+16x+32[/tex]
The area of the colored triangles is [tex](2x^2+16x+32)\ \text{sq. inches}[/tex]