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42. A triangle has an area of 14 square inches. The height of the triangle is three inches more than the
base. What are the base and height of the triangle?
43. Jill has a small treasure box that is 6 inches long. It can hold a volume of 72 inches cubed, and the
width of the box is 5 inches less than twice the height of the box. What are the dimensions of the box?
44. Jessie is mowing her back yard that is in the shape of a right triangle. The shortest side is 7 meters
shorter than the second side, and the hypotenuse is 13 meters long. What are the lengths of the two
sides?

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semsee45

Answer:

Question 42

area of a triangle = 1/2 × base × height

Given:

  • area = 14 in²
  • height = x + 3
  • base = x

Substituting given values into the formula:

⇒ 14 = 1/2 × x × (x + 3)

⇒ 28 = (x + 3)x

⇒ 28 = x² + 3x

⇒ x² + 3x - 28 = 0

⇒ (x - 4)(x + 7) = 0

⇒ x = 4, x = -7

As length is positive, x = 4 only.

⇒ height = 4 + 3 = 7 in

⇒ base = 4 in

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Question 43

volume of a cuboid = length x width x height

Given:

  • volume = 72 in³
  • length = 6 in
  • height = x
  • width = 2x - 5

Substituting given values into the formula:

⇒ 72 = 6 × (2x - 5) × x

⇒ 12 = (2x - 5)x

⇒ 12 = 2x² - 5x

⇒ 2x² - 5x - 12 = 0

⇒ (x - 4)(2x + 3) = 0

⇒ x = 4, x = -1.5

As length is positive, x = 4 only.

⇒ height = 4 in

⇒ width = 2(4) - 5 = 3 in

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Question 44

Pythagoras' Theorem: a² + b² = c²

(where a and b are the legs, and c is the hypotenuse, of a right triangle)

Given:

  • a = x - 7
  • b = x
  • c = 13 m

Substituting given values into the formula:

⇒ (x - 7)² + x² = 13²

⇒ x² - 14x + 49 + x² = 169

⇒ 2x² - 14x - 120 = 0

⇒ x² - 7x - 60 = 0

⇒ (x - 12)(x + 5) = 0

⇒ x = 12, x = -5

As length is positive, x = 12 only.

⇒ one leg = 12 m

⇒ other leg = 12 - 7 = 5 m

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