Answer:
Step-by-step explanation:
<u>Heron's Area formula:</u>
- A = , where s is semi-perimeter
- s = 1/2(a + b + c)
We are given two sides and the included angle.
<u>Use the law of cosines to find the missing side:</u>
- a² = b² + c² - 2bccos A
- a² = 77² + 41² - 2*77*41*cos 79
- a² = 6405
- a = 80 (rounded)
<u>Now find the value of s:</u>
- s = 1/2(80 + 77 + 41) = 99
<u>Find the area:</u>
- A = = = 1549.24
Answer: 389 is the square root.
by using the integration formula
we get,
now put the value of t=\sin\theta in the above equation
we get,
hence proved