The sides of a rectangular object floor are × m and (×+7) m. The diagonal is (×+8) m, calculate, in metres: i. the value of × ii. the area of the floor About the author Evelyn
Answer: Using Pythagoras Theorem x^2 + (x + 7)^2 = (x + 8)^2 x^2 + x^2 + 14x + 49 = x^2 + 16x + 64 Collect like terms: x^2 + x^2 – x^2 + 14x – 16x + 49 – 64 = 0 x^2 – 2x – 15 = 0 Factorise (x + 3)(x – 5) = 0 x + 3 = 0 x = -3 (Disregard as -ve value) x – 5 = 0 x = 5. Area of floor will be x(x + 7) = 5(5 + 7) = 60 m^2 Reply
Answer:
Using Pythagoras Theorem
x^2 + (x + 7)^2 = (x + 8)^2
x^2 + x^2 + 14x + 49 = x^2 + 16x + 64
Collect like terms:
x^2 + x^2 – x^2 + 14x – 16x + 49 – 64 = 0
x^2 – 2x – 15 = 0
Factorise
(x + 3)(x – 5) = 0
x + 3 = 0
x = -3 (Disregard as -ve value)
x – 5 = 0
x = 5.
Area of floor will be x(x + 7)
= 5(5 + 7)
= 60 m^2