
Pls help to solve thx
Pls help to solve thx
Ah…sorry I read the question too quickly…it said “ALL AROUND” the rectangular card…. I just used the picture and started on working the area….hence missing out many more semi-circles…
Moral of the story, must read the entire question and not just look at the picture….I was tricked…lol
Perimeter = 72
2(24 + b ) =72
2b = 72-48 = 24 => b = 12
Area of rectangle = 12 x 24 = 288
Semi-circles along the length = (24/3) x 2 = 16
Semi-circles along the breadth = (12/3) x 2 =8
The A, B, C , D is made up of 2 semi-circles.
Hence total semi-circles = 16+8+2 = 26
Area of 26 semi-circles = [26 x π x (1.5) x (1.5)] / 2 = 91.89
Hence total area of card = 288 + 91.89 = 379.89cm2
Ah…sorry I read the question too quickly…it said “ALL AROUND” the rectangular card…. I just used the picture and started on working the area….hence missing out many more semi-circles…
Moral of the story, must read the entire question and not just look at the picture….I was tricked…lol
Perimeter = 72
2(24 + b ) =72
2b = 72-48 = 24 => b = 12
Area of rectangle = 12 x 24 = 288
Semi-circles along the length = (24/3) x 2 = 16
Semi-circles along the breadth = (12/3) x 2 =8
The A, B, C , D is made up of 2 semi-circles.
Hence total semi-circles = 16+8+2 = 26
Area of 26 semi-circles = [26 x π x (1.5) x (1.5)] / 2 = 91.89
Hence total area of card = 288 + 91.89 = 379.89cm2
This is the answer
Thanks, got it.