MENSURATION FORMULAES

















TRIANGLE

 1. AREA = 1/2*BASE*HEIGHT   OR,

√[s(s-a)(s-b)(s-c)]

 WHERE a, b, c  ARE THE LENGTHS OF THE SIDES OF TRIANGLE AND 

 s=(s+b+c)/2

2. AREA OF AN EQUILATERAL TRIANGLE = √3/4 * (side)^2

3. AREA OF AN ISOSCELES TRIANGLE = b/4 √4(a^2)-(b^2)

4. PERIMETER OF AN EQUILATERAL TRIANGLE = 3 * SIDE

RECTANGLE

 1. AREA = LENGTH * BREADTH

2. PERIMETER = 2 (LENGTH + BREADTH)

3. DIAGONAL = √(LENGTH)^2 + (BREADTH)^2

4. AREA OF PATH (OUTSIDE THE RECTANGLE) = 2 * (LENGTH + BREADTH + 2x)
WHERE x= WIDTH OF THE PATH

5. AREA OF THE PATH INSIDE OF THE RECTANGLE = 2 * (LENGTH + BREADTH -2x)
WHERE x= WIDTH OF THE PATH

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