To find the area of a trapezoid, Dylan uses the formula a= 1/2(b1 + b2)h The bases have lengths of 3.6 cm and 12 1/3 cm. The height of the trapezoid is the square root of 5 cm. The area of the trapezoid is irrational because

Respuesta :

b1 + b2 =
[tex] \frac{36}{10} + \frac{37}{3} = \frac{108}{30} + \frac{370}{30} = \frac{478}{30} [/tex]
1/2(b1 + b2) =
[tex] \frac{478}{60} [/tex]
We now have a =
[tex] \frac{478}{60} \sqrt{5} [/tex]
Assume a is rational.

Then for some integers x and y, y not equal to zero

[tex] \frac{x}{y} = \frac{478}{60} \sqrt{5} [/tex]
Dividing both sides by
[tex] \frac{478}{60} [/tex]
we obtain
[tex] \frac{60x}{478y} = \sqrt{5} [/tex]
Since a rational number cannot equal an irrational number our original assumption that a was rational was false.

a is irrational.

Answer:

Because the irrational number can not be expressed as the ratio of two integers and it is not an imaginary number.

Step-by-step explanation:

Given

The length of one base of trapezoid = 3.6cm =

The length of other base of trapezoid =[tex]12\frac{1}{3}[/tex]=[tex]\frac{37}{3}[/tex]

The height of trapezoid= [tex]\sqrt{5}[/tex] cm

By using formula of area of trapezoid, a=[tex]\frac{1}{2} (b_1+b_2)\times h[/tex]

Substitute the value of [tex]b_1, b_2[/tex] and h in the formula of area of trapezoid

Area of trapezoid=[tex]\frac{1}{2} (\frac{36}{10} +\frac{37}{3} )\times \sqrt{5}[/tex]

Area of trapezoid=[tex]\frac{1}{2} (\frac{108+370}{30}) \times \sqrt{5}[/tex]

Area of trapezoid=[tex]\frac{1}{2} \times \frac{478}{30} \times\sqrt{5}[/tex]

Area of trapezoid=[tex]\frac{239}{30} \sqrt{5}[/tex] [tex]cm^2[/tex]

Let a and b are two integers and let area of trapezoid is rational number

Therefore, the rational number can be write in the ratio of two integers a and b

[tex]\therefore \frac{239}{30} \sqrt{5}=\frac{a}{b}[/tex] where [tex]b \neq 0[/tex]

[tex]\frac{30a}{239b} =\sqrt{5}[/tex]

We know that [tex]\sqrt{5}[/tex] is a irrational number and [tex]\frac{30a}{239b}[/tex] is a rational number

Irrational number can never be equal to rational number

Therefore, the area of trapezoid is irrational number.