Thursday 22 September 2011

CAT concept: Triangles

In most of the CAT or any other MBA questions, geometry remains as significant portion. At same time, most of the question in CAT deals with variety of shapes and not to any particular shape. To deal with such question it is important to understand each shape differently. So we shall focus on different shapes and its characteristics. Failing to understand this is the major reason for not doing well at this section. 






Shape of the day : Triangle

Triangle is a closed figure having three side. We don't need very precise definition. In fact we don't need definition at all! There are three kinds of triangle:

  • Acute : If all three angles are less than 90 degree, such triangle is called right triangle

  • Obtuse : If any one angle is greater 90 degree, it is called obtuse triagle.

  • Right: If any one angle is equal to 90 degree, it is called right triangle.



Sum of all the three angles is 180 degree.
Sum of length of two shorter side is always greater than the longest side.

Area  = 1/2 * base * height

If all the sides are equal then such triangle is called equilateral triangle. Each angle of equilateral triangle is 60 degree.


Angle opposite to the longer side is always greater and angle opposite to smaller site is always smaller.
So we can further conclude that angles opposite to equal sides are equal. A triangle is said to be isosceles if two of the three sides are equal.



If all the three side are different it is called scalene.

Wednesday 21 September 2011

Geometry - 1

Geometry has yet another concept that is begin tested each year. And just like any other quant concept, you need to absorb it all inside you. But at same time geometry for quant demands the logical thinking. Simply knowing the rules of geometry that what angle is equal to what is may not help. You need to know ow to apply it?

Many students, particularly who has left geometry long back as they took humanities or commerce may find this bit difficult. But let me tell you - ITS INTERESTING!







Let us start!

This session will be about some basics of angles. Very elementary. But as I can't scan my prepared material due to lack of time (assignments has to be submitted). I will hopefully scan tomorrow.



Alternate interior angles are equal.


Corresponding angles are equal.




Linear pair => Angle 1 + Angle 2 = 180 degree