The curved part of this figure is a semicircle. What is the best approximation for the area of this figure?
(A). 21+7.25π units²
(B). 21+14.5π units²
(C). 10.5+7.25π units²
(D). 10.5+14.5π units²

The curved part of this figure is a semicircle What is the best approximation for the area of this figure A 21725π units B 21145π units C 105725π units D 105145 class=

Respuesta :

Answer:

The answer is the option

[tex](10.5+7.25\pi)\ units^{2}[/tex]

Step-by-step explanation:

we know that

the area of the figure is equal to the area of semicircle plus the area of a triangle

Find the area of semicircle

we know that

The area of semicircle is equal to

[tex]A1=\frac{1}{2}\pi r^{2}[/tex]

Let

[tex]A(-5,-2), B(2,1)[/tex]

The distance AB is equal to the diameter of semicircle

the formula to calculate the distance between two points is equal to

[tex]d=\sqrt{(y2-y1)^{2}+(x2-x1)^{2}}[/tex]

substitute the values

[tex]d=\sqrt{(1+2)^{2}+(2+5)^{2}}[/tex]

[tex]d=\sqrt{(3)^{2}+(7)^{2}}[/tex]

[tex]dAB=\sqrt{58}\ units[/tex]  -----> diameter of the semicircle

so the radius is equal to

[tex]r=0.5\sqrt{58}\ units[/tex]

find the area of semicircle

[tex]A1=\frac{1}{2}\pi (0.5\sqrt{58})^{2}[/tex]

[tex]A1=\frac{1}{8}\pi (58)[/tex]

[tex]A1=7.25\pi\ units^{2}[/tex]

Find the area of the triangle

[tex]A2=\frac{1}{2}bh[/tex]

we have

Observing the figure

[tex]b=7\ units[/tex]

[tex]3=3\ units[/tex]

substitute

[tex]A2=\frac{1}{2}*7*3=10.5\ units^{2}[/tex]

Find the area of the figure

[tex]A=A1+A2[/tex]

substitute

[tex]7.25\pi\ units^{2}+10.5\ units^{2}\\ \\(10.5+7.25\pi)\ units^{2}[/tex]