Question

The side of a triangles are 8cm,12cm,17cm.find its perimeter and its are by using herons formula

Answer 1

Answer:

see explanation

Step-by-step explanation:

The perimeter is the sum of the 3 sides, that is

perimeter = 8 + 12 + 17 = 37 cm

To use Heron's formula for area (A)

A = $\sqrt{s(s-a)(s-b)(s-c)}$

where a, b and c are the lengths of sides and s the semi perimeter

s = 37 ÷ 2 = 18.5

let a = 8, b = 12 and c = 17, then

A = $\sqrt{18.5(18.5-8)(18.5-12)(18.5-17)}$

   = $\sqrt{18.5(10.5)(6.5)(1.5)}$

   = $\sqrt{1893.9375}$ ≈ 43.52 cm² ( to 2 dec. places )

Answer 2

Hi!

Heron's formula:

$s = \dfrac{a+b+c}{2}$

Area = $\sqrt{s(s-a)(s-b)(s-c)}$

Perimeter = 8 + 12 + 17 = 37 cm

$s = \dfrac{37}{2} = 18.5$

Area = $\sqrt{18.5(18.5-8)(18.5-12)(18.5-17)} = \sqrt{18.5 * 10.5 * 6.5 * 1.5} = \sqrt{1893,9375}$

[tex]\sqrt{1893.9375} ≈ 43.52

Area ≈ 43.52 cm²

Wish Good Lessons! ^-^