Question

00
:
Q 24. The perimeter of the following shape
(in meters) is
5 m
2 m
8 m
14 m
A) 34
B) 44
C) 48
D) 46​

Answer 1

Answer:

Explanation:

• Rectangle

(a) Area = length × breadth

(b) Perimeter = 2 (length + breadth)

(c) Diagonal = ( )( ) 2 2 length + breadth

• Square

(a) Area = (side)2

(b) Perimeter = 4 × side

(c) Diagonal = 2 × side

• Triangle with base (b) and altitude (h)

Area =

1

2

× ×b h

• Triangle with sides as a, b, c

(i) Semi-perimeter = 2

abc

s

+ + =

(ii) Area = ss a s b s c ( )( )( ) ––– (Heron’s Formula)

• Isosceles triangle, with base a and equal sides b

HERON’S FORMULA

CHAPTER 12

16/04/18 16/04/18

Area of isosceles triangle = 2 2 4 –

4

a b a

• Equilateral triangle with side a

Area = 3 2

4

a

• Parallelogram with base b and altitude h

Area = bh

• Rhombus with diagonals d1

and d2

(a) Area = 1 2

1

2

d d ×

(b) Perimeter = 2 2

1 2 2 d d +

• Trapezium with parallel sides a and b, and the distance between two parallel

sides as h.

Area =

1

2 (a + b) × h

• Regular hexagon with side a

Area = 6 × Area of an equilateral triangle with side a

= 3 2 6

4

× a = 3 2 3

2

a