1. Area of a rectangle = (Length × Breadth).
I). Area of a triangle = √s(s-a)(s-b)(s-c) where a, b, c are the sides of the triangle and s = 1/ 2 (a + b + c)
II). Area of parallelogram = (Base x Height).
Area of a rhombus = 1 / 2 (Product of diagonals).
III). Area of a trapezium =1 / 2 (sum of parallel sides) x distance between them.
Iv). Area of a circle = ΠR2, where R is the radius.
I). Circumference of a semi-circle = ΠR.
II). Area of semi-circle = ΠR2 / 2.
Results on Triangles :
1. Sum of the angles of a triangle is 180°.
2. The sum of any two sides of a triangle is greater than the third side.
3. Pythagoras Theorem : In a right-angled triangle, (Hypotenuse)2=(Base)2 + (Height)2.
4. The line joining the mid-point of a side of a triangle to the positive vertex is called the median.
2. The sum of any two sides of a triangle is greater than the third side.
3. Pythagoras Theorem : In a right-angled triangle, (Hypotenuse)2=(Base)2 + (Height)2.
4. The line joining the mid-point of a side of a triangle to the positive vertex is called the median.
