Answer:
40 ft
Step-by-step explanation:
Perimeter is the sum of all 3 sides of a triangle.
For this particular triangle, add 8+20+12:
40
Answer: A 18 1/5 - 22 2/5 - 40 1/5
Answer:
x = 3 or x = 1
Step-by-step explanation:
Solve for x over the real numbers:
x^2 - 4 x + 3 = 0
Subtract 3 from both sides:
x^2 - 4 x = -3
Add 4 to both sides:
x^2 - 4 x + 4 = 1
Write the left hand side as a square:
(x - 2)^2 = 1
Take the square root of both sides:
x - 2 = 1 or x - 2 = -1
Add 2 to both sides:
x = 3 or x - 2 = -1
Add 2 to both sides:
Answer: x = 3 or x = 1
Answer:
Both answers will give an area of 2400 ft2
but with x=60 we have lawn dimensions -60 ft by -40 ft so this is out
x = 10 ft width for the sidewalk
Check: New lawn dimensions
(80-2x)(60-2x) = 60(40) = 2400 ft^2
Step-by-step explanation:
Draw a diagram:
We have a rectangle inside a rectangle.
The larger outside rectangle is the original lawn: 80ft by 60 ft with area 4800 ft2
The smaller inside rectangle is (80-2x)by(60-2x) where x is width of the new sidewalk.
Area of new lawn is 2400 ft^2
(80-2x)(60-2x) = 2400
4800 - 160x - 120x + 4x2 = 2400
4x2 - 280x + 2400 = 0
Factor out a 4
x2 - 70x + 600 = 0
(x-60)(x-10) = 0
x = 60 ft or x = 10 ft
Least 1.2, 1.26, 1.3 greatest
