iMath | Community

Winnie Win

Asked 9 years ago

SG Primary 6 Measurement

Replies 5

Gerald Goh

The diameter of semicircle BOC can be derived using the Area of Square = Area of 2 Triangle ABC. Diameter = square root 50

6 years ago

Winnie Win

Thanks Gerald Goh. My dd hasn't learnt sq root yet and calculator not allowed. My ans got decimal.

6 years ago

Gerald Goh

Is this a P5 question?

6 years ago

Winnie Win

P6

6 years ago

Pieter Cronje

Sqroot of 50 is very close to 49...so i suggest using 7 .

6 years ago

Elsie Tan

Asked 9 years ago

SG

Thanks for accepting.

Replies 0

Philip Chua

Asked 9 years ago

SG

Dear All, I have a problem with this question and do not know how to solve it. Can someone help, please?? Thank you.

Replies 3

Soo Vei Li

385 = 5 x 7 x 11. These prime factors can be used to form the L and B of rectangles (385 is the area of the rectangle) 35 x 11, 5 x 77 and 55 x 7. And there is also 1 x 385. So there are 4 ways.

6 years ago

Jojo Celestino

basically, the 385 identical squares can be considered as tiles that you need to put together in order to form rectangles. since you need to use all 385 tiles to make a rectangle, you can say that the area of your rectangle must be 385 square units.. now that you know the rectangle's area, the thing left for you to do is identify the different dimensions that will give an area of 385 square units.. there can be more than one set of dimensions that can satisfy this requirement.. Here are the possible sets of dimensions: length = 1 unit breadth = 385 units area = 385 square units length = 5 units breadth = 77 units area = 385 square units length = 7 units breadth = 55 units area = 385 square units length = 11 units breadth = 35 units area = 385 square units Since you can only come up with 4 sets, that means you can have 4 different rectangles.. This problem combines the concepts of area of a rectangle and factors.. The specific heuristics that can be used are guess&check and making a systematic list.. Hope this helps! :)

6 years ago