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PLEASe help math ...

PLEASe help math ...-example-1
User Cmrn
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2 Answers

21 votes
21 votes

Area of the trapezium

  • 1/2(Sum of parallel sides)×Height
  • 1/2(2+8)(4)
  • 2(10)
  • 20units²

Area of semicircle

  • π(2/2)²/2
  • π/2
  • 1.57units²

Total area

  • 20+1.57
  • 21.6units²(Rounded)
User Thijs
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2.7k points
14 votes
14 votes

Answer:

21.6 units² (nearest tenth)

Explanation:


\textsf{Area of a trapezoid}=(1)/(2)(a+b)h \quad \textsf{(where a and b are the bases and h is the height)}
\textsf{Area of a semicircle}=\frac12 \pi r^2 \quad \textsf{(where r is the radius)}

Given:

  • a = 2
  • b = 8
  • h = 4
  • r = 2 ÷ 2 = 1


\begin{aligned}\textsf{Area of figure} & =\textsf{area of trapezoid + area of semicircle}\\& = (1)/(2)(a+b)h+(1)/(2) \pi r^2\\& = (1)/(2)(2+8)(4)+(1)/(2) \pi (1)^2\\& = 20+(1)/(2) \pi\\& = 21.6\: \sf units^2 \:(nearest\:tenth)\end{aligned}

User Hemeroc
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