Page 179 - Math_Genius_V1.0_C6_Flipbook

E:\Working\Focus_Learning\Math_Genius-6\Open_Files\09_Chapter_6\Chapter_6
\ 07-Nov-2024 Bharat Arora Proof-8 Reader’s Sign _______________________ Date __________

Knowledge Desk
Mathematician (Leonard Digges — Father Of Mensuration)
Leonard Digges is known as the Father of Mensuration because he made measuring
things easier. In his book ‘Pantometria’, he showed how to measure shapes like
triangles and circles. He also developed new formulas for calculating areas and
volumes. Using simple drawings, he explained these ideas clearly. His book was
one of the first to focus only on measuring things, which made it really famous.
People started using his methods in various fields, such as building and engineering.
Digges basically created the rules for measuring stuff, which is why he is called as
the Father of Mensuration.

Quick Check

Find the perimeter of each of the following figures.
1. 60 m 2. 6 m
2 m 1 m
2 m 1 m
2 m 1 m
30 m
8 m
35 m
5 m

25 m
15 m 12 m
40 m

Perimeter of a Rectangle

Consider a rectangle STUV whose length and breadth are 10 cm and 4 cm, respectively.

S 10 cm T

4 cm 4 cm

V 10 cm U

Perimeter of the rectangle STUV = Sum of the lengths of its four sides
= ST + TU + UV + VS

= ST + TU + ST + TU [Q ST = UV and TU = SV]

= 2ST + 2TU
= 2(ST + TU) = 2(10 cm + 4 cm) = 2(14 cm) = 28 cm.

So, the perimeter of the rectangle STUV = 2(length + breadth) = 28 cm

Thus, we conclude that the perimeter of a rectangle = 2(length + breadth)

177
177 P erimeter and Ar ea
Perimeter and Area