Respuesta :

Answer:

A. 41

B. 1,590

C. .1

Step-by-step explanation:

A.

the equation is l*w=A

9.2*4.5=A

41.4=A

rounded it would be 41

B.

the equation is pi*r^2=A

3.14*22.5^2=A

3.14*506.25=A

1,589.6=A

^round this up to get 1,590

C.

what I did was use a*b/2 to find one side then add the other side (less complicated in my opinion)

.5*.2/2=A

.1/2=A

.05=A

.05+.05=0.1

Answer:

[tex]\text{a. }41.4\:\mathrm{m^2},\\\text{b. }1590.4\:\mathrm{cm^2},\\\text{c. }0.1\:\mathrm{m^2}[/tex]

Step-by-step explanation:

Part A:

The figure implies a rectangle. The area of a rectangle with base [tex]b[/tex] and height [tex]h[/tex] is given by [tex]A=bh[/tex].

What we're given:

  • [tex]b[/tex] of 9.2
  • [tex]h[/tex] of 4.5

Therefore, the area of the rectangle is [tex]9.2\cdot 4.5=\boxed{41.4\:\mathrm{m^2}}[/tex]

Part B:

The figure shows a circle. The area of a circle with radius [tex]r[/tex] is given by [tex]A=r^2\pi[/tex]. In the figure, the diameter is marked as 45 cm. To find the radius, we must divided this by 2, because by definition, the radius if half the diameter. Therefore, [tex]r=\frac{45}{2}=22.5\:\mathrm{cm}[/tex] and the area of this circle, rounded to the nearest tenth, is [tex]22.5^2\pi=1590.43128088\approx \boxed{1590.4\:\mathrm{cm^2}}[/tex]

Part C:

The figure shows a triangle (polygon with three sides). The area of a triangle with base [tex]b[/tex] and height [tex]h[/tex] is given by [tex]A=\frac{1}{2}bh[/tex].

What we're given:

  • [tex]b[/tex] of 0.4
  • [tex]h[/tex] of 0.5

Substituting given values, we get:

[tex]A=\frac{1}{2}\cdot 0.4\cdot 0.5=\boxed{0.1\:\mathrm{m^2}}[/tex]