Question

These figures are similar . The perimeter and area of one are given. The perimeter of the other is also given. Find its area and round to the nearest tenth . imeter = 20cm; Area = 18.6c * m ^ 2 Perimeter ater = 28cm; Area=[ ? ] cm^ 2

Answer 1

≈ 36.5 cm²

Explanation:

given 2 similar figures with ratio of perimeters = a : b , then

ratio of areas = a² : b²

ratio of perimeters = 20 : 28 = 5 : 7 , then

ratio of areas = 5² : 7² = 25 : 49

let x be the required area then by proportion

`(18.6)/(x)` =
`(25)/(49)` ( cross- multiply )

25x = 911.4 ( divide both sides by 25 )

x = 36.456

then area of shape is approx 36.5 cm² ( to the nearest tenth )