Find the perimeter of a triangle with sides equal to 6 cm, 4 cm and 5 cm.

Given that, a = 8 cm, b = 10 cm and c = 12 cm

We know, that
s = (a + b + c)/2
= (8 + 10 + 12)/2
= 30/2 = 15 cm

? (s - a) = (15 - 8) = 7 cm
(s - b) = (15 - 10) = 5 cm
(s - c) = (15 - 12) = 3 cm

? Area = ?s(s - a) (s - b) (s - c)
= ?15 x 7 x 5 x 3
= ?1575
= ?25 x 63
= 5?63 cm

Req. Area = ?3/4 x a² = ?3/4 x 8² cm²
= 16?3 cm²

Area of equilateral triangle = ?3/4 a² = 4?3.
? a² = 16
? a = 4 cm

Ratio of area = a²/ ?(3/4) a²
= 4/?3 = 4:?3

Original area = ?(d/2)²
= (?d²) / 4

New area = ?(2d/2)²
= ?d²

Increase in area = (?d² - ?d²/4)
= 3?d²/4

? Required increase percent
= [(3?d²)/4 x 4/(?d²) x 100]%
= 300%

Given that,
area = 40 sq cm,
base = 28 cm and
height = perpendicular = ?

Area = (base x perpendicular) / 2
? 40 = (28 x perpendicular) / 2
? perpendicular = 40/14 = 20/7
= 2⁶/₇ cm

Given that, area = 10 sq cm,
perpendicular = 20 cm and base = ?
area = (base x Perpendicular) / 2
? 10 = (base x 20) / 2
? base = 1 cm

Area of parallelogram = Base x Height
= 8.06 x 2.08 = 16.76 cm²

Required area = Length x Breadth
= 15 x 8 = 120 sq m

Required area = Length x Breadth
= 100 x 40 = 4000 sq m
= 4 x 10³ sq m