How do you solve the triangle given trianglePQR, p=12, q=16, r=20?

1 Answer
Nov 29, 2017

18.97 (2.d.p)

Explanation:

As we are given 3 sides of the triangle, with no right angle, we can use Heron's formula to solve for the area. Heron's formula can be used when we know the 3 sides of a triangle, which in this case we know p, q and r.

Heron's formula: A = sqrt(s-(s-a)(s-b)(s-c)

where s = (a+b+c)/2 (half perimeter of the triangle)

In this case, we can assume a, b and c = p, q and r respectively.

So, s=(12+16+20)/2
= 24

Now, we just plug the numbers into Heron's formula to get the area of the triangle.

A = sqrt(24-(24-12)(24-16)(24-20)
= 18.97 (rounded to two decimal places)