The sides of triangles PQR and ABC are given; PQ = 16cm, QR = 20cm, PR = 28cm and AB = 12cm,
The sides of triangles PQR and ABC are given; PQ = 16cm, QR = 20cm, PR = 28cm and AB = 12cm, BC = 15cm, AC = 21cm. Find the ratio of the areas of these triangles
To solve the problem, we use Heron’s formula, which allows us to find the area of any triangle along its sides:
S = √p (p – a) (p – b) (p – c);
Here p is half of the perimeter p = (a + b + c) / 2;
Let’s calculate what these values are for each of the triangles:
Triangle ABC
R
(12 + 15 + 21) / 2 =
48
p – a
48 – 12 =
36
p – b
48 – 15 =
33
p – with
48 – 21 =
27
p (p – a) (p – b) (p – c)
48 × 36 × 33 × 27 =
1,539,648
S
√ 1 539 648
1240,7852
PQR triangle
R
(16 + 20 + 28) / 2 =
32
p – a
32 – 16 =
sixteen
p – b
32 – 20 =
12
p – with
32 – 28 =
4
p (p – a) (p – b) (p – c)
32 × 16 × 12 × 4 =
24,576
S
√ 24,576
156.7673
Find the area ratio:
SABC / S PQR = 1241: 157 = 7.9;