Speed with Accuracy for solving questions is the key to success in these tests. These tricks for solving problems will not only help you in saving time but also accuracy.

Here are some important formulas for triangles.

A. area of any triangle:

a. Area of a triangle =1/2 x Base x Height.

b. Area of a triangle = root(s(s-a)(s-b)(s-c))

where s = (a + b + c)/2

and a, b, c are the sides of the triangle.

2. Equilateral triangle area= [root (3)/4]*side^2

Equilateral triangles height (h) = (root3 /2) *a

3. Area of an Isosceles triangle = (b/4) * root (4a^2 – b^2)

Where a= one of two equal sides of isosceles triangle.

And b= third side of isosceles triangle (not equal to two sides).

**B. INCIRCLE AND CIRCUM CIRCLES: Formulas for calculating Incircles and circum circles of Triangles**

1. Radius of incircle of an equilateral triangle = a /(2root3)

Where a=side

2. Radius of circumcircle of an equilateral triangle = a/root3

3. Radius of incircle of a Scalene triangle of area P and semi-perimeter s = P/s

And Radius of Circum-circle of Scalene triangle = (a*b*c)/(4*area)

Where a, b, c are sides of scalene triangle.

C. In a right angled triangle: Pythagoras theorem

Hypotenuse)^2 = (Perpendicular)^2 + (Base)^2

**D. PERIMETER : Triangle formulas for calculating perimeter**

1. Scalene triangle perimeter = a+b+c

Where a,b,c are the sides of triangle.

2. Isoceles triangle perimeter = 2a+b

Where a=one of two equal sides

And b= 3rd unequal side

3. equilateral = 3a