• Jun 10th 2012, 11:57 AM
diva19871987
Hi, I am rather sh*t at maths and I left school years ago and recently decided to go back to college to do the most basic foundation maths course. The key word here being foundation which is generally the easiest in th UK. The thing is though is I just do not have a clue and I have my exam TOMMOROW!!! Im trying to do some past papers and at the minute I doubt there would be any point turning up tomorrow because even though Ive always been a bit poor at maths but Ive now turned into someone who hasnt GOT A CLUE!!

I have given up on algebra all together because it just seems like an impossible task. The more I try the more confused I become. I have litterally tried to understand for weeks on end and have gotten NO WHERE!!

Anyway back to the past papers I am trying to do. One of the questions is-

This shape is made from a rectangle and a semicircle.

(Imagine a rectangle with a semicircle joined onto the top of the rectangle length ways?? Sorry dont know how I draw it on here!!)

Ive got to give the area for the whole shape. Now Im given 16cm for the lenght of the rectangle and 12cm for the height of the whole shape. Im not given the height of the semicircle or rectangle and the height altogether is 12cm. I dont know how i work this out. The base of the semicircle would be 16cm same as the rectangle im guessing.

Please dont think im thick because maybe i am but i am just struggling to work this out! It is worth 5 points so would be a big difference if i didnt know how to do it.

• Jun 10th 2012, 12:12 PM
Reckoner
Is tomorrow the final exam? It sounds like you might have to repeat this course. I don't think we can offer the level of help that you need, especially not in a single day.

Quote:

Originally Posted by diva19871987
Ive got to give the area for the whole shape. Now Im given 16cm for the lenght of the rectangle and 12cm for the height of the whole shape. Im not given the height of the semicircle or rectangle and the height altogether is 12cm. I dont know how i work this out. The base of the semicircle would be 16cm same as the rectangle im guessing.

If the base of a semicircle is 16 cm, then what is its radius?

And, knowing the radius, one can find the height of the rectangle by subtracting from 12...
• Jun 10th 2012, 12:13 PM
BobP
If you know the 'base of the semicircle', you know its radius and if you know the semicircles radius you should be able to calculate the height of the rectangle. Therefore you have the dimensions of the rectangle and should be able to work out its area and if you know the radius of the semicircle you should be able to work out its area as well, (its half the area of the circle having the same radius).
Add the two areas together and you have the area of the whole figure.
• Jun 10th 2012, 02:14 PM
diva19871987