In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data:
equilateral triangle:
side = 7x
circle:
radius = 4r
Step 02:
area:
a = circle area - triangle area
triagle area:
triagle area = (b * h) / 2
b = 7x
h:
[tex]\begin{gathered} (7x)^2=h^2+(\frac{7x}{2})^2 \\ 49x^2=h^2+\frac{49x^2}{4} \\ h^2=49x^2-\frac{49x^2}{4}=\frac{147x^2}{4} \\ h\text{ = }\sqrt[]{\frac{147x^2}{4}\text{ }}=6.06x=6.1x \end{gathered}[/tex]h = 6.1x
[tex]\text{triangle area = }\frac{7x\cdot6.1x}{2}=\frac{42.7x^2}{2}=21.35x^2[/tex]circle area:
circle area (r) = π r² = π (4r)² = 16 π r²
a = circle area - triangle area
a = 16 π r² - 21.35x²
The answer is:
a = 16 π r² - 21.35x²
