CH.11

MENSURATION

The Area, Perimeter and Volume of triangle,

rectangles, circles etc. are known as

mensuration.

MENSURATION

Shapes names perimeter

Square Side × side

Rectangle 2 ( L + B )

Circle 2π

Triangle L + B + H

PERIMETER

Diagram Shapes Area Rectangle A × A

Square B × H Triangle πb2

Parallelogram 1 b × h 2

Area

Circle a × b

Example of areaArea of square = B × h

= 25 × 25 =625 m

AREA OF -

(i) a trapezium = half of the sum of the lengths of parallel sides × perpendicular distance betweenthem.(ii) a rhombus = half the product of its diagonals.

= cuboid

= cylinder

= cube

cone = pyramid

Solids shapes

Surface area of a solid is the sum of the areas of

its faces.

SURFACE AREA OF SOLID SHAPES

A cuboid = 2( LB+BH+HL )

SURFACE AREA OF CUBOID

SURFACE AREA OF CUBE

A cube = 6l square

SURFACE AREA OF CYLINDER

A cylinder = 2πr(r + h)

Amount of region occupied by a solid is

called its volume

VOLUME

VOLUME OF CUBOID

A cuboid = l × b × h

VOLUME OF CUBE

A cube = L× L× L

VOLUME OF CYLINDER

A cylinder = πr × r h

PRESENTED BY KONDETI YASHWANT