the question was find the perimeter of a rectangle when the area is 80cm^2 and one side is 5cm
2007-05-23 09:12:12 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Say the length of the sides of the rectangle are called 'a' and 'b'.
The formula for the area = a*b
The formula for the perimeter = 2a + 2b
We know that one side is 5cm long. We'll call this 'a'.
So, 5*b = 80, which means b = 16 cm.
The perimeter then is 2(5) + 2(16) = 42cm.
2007-05-23 09:17:53 · answer #1 · answered by clipside1234 1 · 0⤊ 0⤋
Area = l * w =
80 = l * 5
l = 16
Perimeter = 2l + 2w = 2*16 + 2*5 = 32 + 10 = 42
2007-05-23 09:19:55 · answer #2 · answered by TychaBrahe 7 · 0⤊ 0⤋
42
2007-05-27 05:32:07 · answer #3 · answered by josemontes4u 1 · 0⤊ 0⤋
square = 4a
rectangle = 2a + 2b
triangle = a + b + c
circle = 2pi r
circle = pi d (where d is the diameter)
The perimeter of a circle is more commonly known as the circumference.
2007-05-23 09:19:44 · answer #4 · answered by cootiebug 1 · 0⤊ 0⤋
just add up all the sides
2007-05-23 09:27:46 · answer #5 · answered by Nana Callie loves to sing 4 · 0⤊ 0⤋