Question

Find the area of a triangle with a=20, b=30, and c=40

Answer 1

Answer:

option C is correct.

Step-by-step explanation:

The area of triangle with sides a, b and c can be found by using formula

$Area = \sqrt{s(s-a)(s-b)(s-c)} \\where \\s= \frac{1}{2}(a+b+c)$

We are given:

a= 20

b=30

c=40

Finding s:

Putting values in the formula and solving:

$s= \frac{1}{2}(a+b+c)\\s=\frac{1}{2}(20+30+40)\\s=\frac{90}{2}\\s= 45$

Now, Finding the area:

Putting values in the formula and solving:

$Area = \sqrt{s(s-a)(s-b)(s-c)}\\Area =\sqrt{45(45-20)(45-30)(45-40)}\\Area =\sqrt{45(25)(15)(5)}\\Area = \sqrt{84,375} \\Area = 290.5 units^2$

So, option C 290.5 units^2 is correct.