Expert: Azeem Hussain - 9/14/2009

Question
QUESTION: Azeem, honestly i have no clue about maths, I really need you help.

1. Please help me to find the area of a cube which has edges of length 5m.

2. The town A is 35km due north of town B. Town C is due east of town B. I have to find the distance from B to C if the distance from A to C is 73km. Give the answer correct to the nearest kilometer.

Please help, and thanking you in advance.

ANSWER: Hello Bongiwe,

A cube's surface area is composed of 6 equal squares.  Find the area of one square and multiply that by 6 to get the cube's total surface area.

Sketch the situation of Towns A, B, and C.  They form a right triangle.  You can solve this problem by the Pythagorean Theorem, c²=a²+b², where c is the length of the longest side.

Glad to help,
Azeem

---------- FOLLOW-UP ----------

QUESTION: but i don't have an idea of what you are talking about. please will you be able to elaborate it with an example each. As I really am confused now.


Answer
Hi Bongiwe,

Unless if you don't know what a square is (in which case tell me), I can't make it much simpler than I already have.  A square's area is found by multiplying the length of one side by itself.  To find the cube's surface area, multiply one square's area by 6.

If you were to draw towns A, B, and C on a map, you would get a right triangle.  A right triangle is one that has a 90-degree angle (aka a right angle).  A mathematician named Pythagoras came up with a theorem that stated that the square of the length of the hypotenuse (longest side) of a right triangle is equal to the sum of the squares of the legs (the other two sides), commonly shown as c²=a²+b.  In this particular case, you need to find a or b:
c²=a²+b
a²=c²-b²
a=(c²-b²)^(1/2)

Now you can plug in the the town distances for b and c.

Hope this helps,
Azeem