For each problem, use the formula for area of a polygon A = 12 ap , where a is the length of the
apothem and p is the perimeter of the polygon, to find the area of the polygon.
Show the exact values of a and p on your figure and give your answers as exact values - no rounding – no decimals. Show all your work clearly. All polygons represented are regular polygons.

For each problem use the formula for area of a polygon A 12 ap where a is the length of the apothem and p is the perimeter of the polygon to find the area of th class=

Respuesta :

Answer:

Part 1) Triangle: [tex]P=24\sqrt{3}\ in[/tex]  and  [tex]A=48\sqrt{3}\ in^2[/tex]

Part 2) Square: [tex]P=40\sqrt{2}\ ft[/tex]  and  [tex]A=200\ ft^2[/tex]

Part 3) Hexagon 1: [tex]P=90\ cm[/tex]  and  [tex]A=\frac{675\sqrt{3}}{2})\ cm^2[/tex]

Part 4) Hexagon 2: [tex]P=540\ m[/tex]  and  [tex]A=12,150\sqrt{3}\ m^2[/tex]

Step-by-step explanation:

Part 1) we have an equilateral triangle

we know that

[tex]A=\frac{1}{2}ap[/tex]

where

a is the apothem

P is the perimeter

step 1

Find the length side of the equilateral triangle

Let

b ----> the length side of triangle

we know that

The measure of each interior angle is 60 degrees

so

[tex]tan(30^o)=\frac{4}{b/2}[/tex] ---> by TOA (opposite side divided by the adjacent side)

[tex]tan(30^o)=\frac{1}{\sqrt{3}}[/tex]

equate

[tex]\frac{4}{b/2}=\frac{1}{\sqrt{3}}[/tex]

[tex]\frac{8}{b}=\frac{1}{\sqrt{3}}[/tex]

[tex]b=8\sqrt{3}\ in[/tex]

step 2

Find the perimeter

[tex]P=3b[/tex]

[tex]P=3(8\sqrt{3})=24\sqrt{3}\ in[/tex]

step 3

Find the area

[tex]A=\frac{1}{2}(4)(24\sqrt{3})=48\sqrt{3}\ in^2[/tex]

Part 2) we have a square

we know that

[tex]A=\frac{1}{2}ap[/tex]

where

a is the apothem

P is the perimeter

step 1

Find the length side of the square

Let

b ----> the length side of the square

we know that

The diagonal is half the radius of the square

Applying the Pythagorean Theorem

[tex]D^2=b^2+b^2[/tex]

[tex]D^2=2b^2[/tex]

we have

[tex]D=2a=2(10)=20\ ft[/tex]

[tex]20^2=2b^2[/tex]

[tex]b^2=200\\b=\sqrt{200}\ ft[/tex]

simplify

[tex]b=10\sqrt{2}\ ft[/tex]

step 2

Find the perimeter

[tex]P=4b=4(10\sqrt{2})=40\sqrt{2}\ ft[/tex]

step 3

Find the area

[tex]A=\frac{1}{2}ap[/tex]

The apothem is half the length side of the square

[tex]a=5\sqrt{2}\ ft[/tex]

[tex]A=\frac{1}{2}(5\sqrt{2})(40\sqrt{2})[/tex]

[tex]A=200\ ft^2[/tex]

Part 3) we have a regular hexagon

we know that

[tex]A=\frac{1}{2}ap[/tex]

where

a is the apothem

P is the perimeter

step 1

Find the length side of the hexagon

we know that

The length side of a regular hexagon is equal to the radius

Let

b ----> the length side of the hexagon

we have

[tex]b=30/2=15\ cm[/tex] ----> the radius is half the diameter

step 2

Find the perimeter

[tex]P=6b=6(15)=90\ cm[/tex]

step 3

Find the area

[tex]A=\frac{1}{2}ap[/tex]

The apothem is the height of an equilateral triangle

Applying the Pythagorean Theorem

[tex]b^2=(b/2)^2+a^2[/tex]

[tex]15^2=(15/2)^2+a^2[/tex]

[tex]a^2=225-(225/4)[/tex]

[tex]a^2=675/4\\a=\frac{\sqrt{675}}{2}\ cm[/tex]

simplify

[tex]a=\frac{15\sqrt{3}}{2}\ cm[/tex]

substitute in the formula of area

[tex]A=\frac{1}{2}(\frac{15\sqrt{3}}{2})(90)[/tex]

[tex]A=\frac{675\sqrt{3}}{2})\ cm^2[/tex]

Part 4) we have a regular hexagon

we know that

[tex]A=\frac{1}{2}ap[/tex]

where

a is the apothem

P is the perimeter

step 1

Let

b ---> the length side of the hexagon

we have

[tex]b=90\ m[/tex]

Find the perimeter

[tex]P=6b=6(90)=540\ m[/tex]

step 2

Find the area

[tex]A=\frac{1}{2}ap[/tex]

The apothem is the height of an equilateral triangle

Applying the Pythagorean Theorem

[tex]b^2=(b/2)^2+a^2[/tex]

[tex]90^2=(90/2)^2+a^2[/tex]

[tex]a^2=8,100-2,025[/tex]

[tex]a^2=6,075\\\\a=\sqrt{6,075}\ m[/tex]

simplify

[tex]a=45\sqrt{3}\ m[/tex]

substitute in the formula of area

[tex]A=\frac{1}{2}(45\sqrt{3})(540)[/tex]

[tex]A=12,150\sqrt{3}\ m^2[/tex]