segitiga abc yg kelilingnya 60 ketiga sisinya masing masing 4x-1, 5x,dan7x-3 berapa luas segitiga tersebut

Bab Bangun Datar

K = a + b + c
60 = 4x - 1 + 5x + 7x - 3
16x - 4 = 60
16x = 60 + 4
x = 64/16
x = 4

a = 4(4) - 1
a = 16 - 1
a = 15 cm

b = 5(4)
b = 20 cm

c = 7(4) - 3
c = 28 - 3
c = 25 cm

Luas segitiga = √(s(s - a)(s - b)(s - c))
Dengan s = 1/2 (a + b + c)

s = 1/2 (15 + 20 + 25)
s = 1/2 (60)
s = 30 cm

Luas
= √(30(30 - 15)(30 - 20)(30 - 25))
= √(30(15)(10)(5))
= √22.500
= 150 cm^2

K= 60
Sisinya 4x-1,5x,7x-3
Keliling= sisinya ditambah semua
60 = 4x-1 + 5x+7x-3
60+4 = 16x
x = 64/16
x = 4

4x-1
4(4)-1 = 15 cm (alas)

5x
5(4)= 20 cm  (tinggi)

7x-3
7(4)-3 = 25 cm (sisi miring)

Luas segitiga = a.t/2
                      = 15.20/2
                      = 150 cm
Maaf klau ada kesalahan