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The area of a triangle reduced by the area of the semicircle is ( 48 - 2π ) square meters. The base of the triangle is 12 meters. Find the height of the triangle and radius of the semicircle.

Answer :

Ashraf82

Answer:

The height of the triangle is 8 meters and the radius of the semi-circle is 2 meters

Step-by-step explanation:

The area of a triangle = [tex]\frac{1}{2}[/tex] × b × h, where

  • b is the length of the base
  • h is the length of the height

The area of a semi-circle =  [tex]\frac{1}{2}[/tex] π r², where

  • r is the length of the radius

∵ The area of the figure = Area Δ - Area semicircle

∵ The area of the figure =  [tex]\frac{1}{2}[/tex] × b × h -  [tex]\frac{1}{2}[/tex] π r²

∵ The base of the triangle is 12 meters

→ Substitute it in the area of the figure above

∴ The area of the figure =  [tex]\frac{1}{2}[/tex] × 12 × h -  [tex]\frac{1}{2}[/tex] π r²

The area of the figure = 6h -  [tex]\frac{1}{2}[/tex] π r²

∵ The area of the figure = 48 - 2 π

→ Equate the two expressions of the area of the figure

6h -  [tex]\frac{1}{2}[/tex] π r² = 48 - 2 π

→ Equate the like terms of the two sides

6h = 48

→ Divide both sides by 6 to find h

h = 8

- [tex]\frac{1}{2}[/tex] π r² = -2 π

→ Divide both sides by -π

∴  [tex]\frac{1}{2}[/tex]  r² = 2

→ Multiply both sides by 2

∴ r² = 4

→ Take √  for both sides

r = 2

The height of the triangle is 8 meters and the radius of the semi-circle is 2 meters

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