Trigonometry
Find the exact area of the triangle with side lengths of 4cm, 5cm and 6cm.
I get the area to be 9.9cm^2.
I get the area to be 9.9cm^2.
Anyone?
Original post by Ano9901whichone
Anyone?
No angles?
http://www.mathopenref.com/heronsformula.html
9.9 is right but it isn't exact
9.9 is right but it isn't exact
Original post by Math12345
I was going to suggest that but Heron's doesn't involve trigonometry and he wants the "exact" answer, so 9.9 is not correct but rather rounded.
https://www.wolframalpha.com/input/?i=sqrt(15%2F2(15%2F2-4)(15%2F2-5)(15%2F2-6))
1. Use Heron's formula
2. Simplify
Unparseable latex formula:
\frac{15\sqrt{7}}{4}}
1. Use Heron's formula
2. Simplify
(edited 7 years ago)
Original post by Ano9901whichone
Find the exact area of the triangle with side lengths of 4cm, 5cm and 6cm.
I get the area to be 9.9cm^2.
I get the area to be 9.9cm^2.
Show your working, you don't necessarily need to use Heron's for this. I got
(edited 7 years ago)
Is Heron's formula GCSE?
I've certainly never came across it, in either GCSE or A Level and had never heard of it before this thread.
Did this by getting the cosine of an angle from the cosine rule, then working out sine of the same angle using SOHCAHTOA, and finally subbing the sine of the angle into the formula 1/2 ab sin C
I've certainly never came across it, in either GCSE or A Level and had never heard of it before this thread.
Did this by getting the cosine of an angle from the cosine rule, then working out sine of the same angle using SOHCAHTOA, and finally subbing the sine of the angle into the formula 1/2 ab sin C
(edited 7 years ago)
Original post by AlexS101
Is Heron's formula GCSE?
I've certainly never came across it, in either GCSE or A Level and had never heard of it before this thread.
Did this by getting the cosine of an angle from the cosine rule, then working out sine of the same angle using SOHCAHTOA, and finally subbing the sine of the angle into the formula 1/2 ab sin C
I've certainly never came across it, in either GCSE or A Level and had never heard of it before this thread.
Did this by getting the cosine of an angle from the cosine rule, then working out sine of the same angle using SOHCAHTOA, and finally subbing the sine of the angle into the formula 1/2 ab sin C
No it's not. I just noticed this is in the GCSE section. Yes what you said is the best way for a GCSE student (I just couldn't be bothered to use the cosine rule and then the area formula)
Quick Reply
Related discussions
- Trapezium question - URGENT help needed!
- gcses
- Does anyone have a gcse maths topic list per paper?
- Cambridge University Maths Additional Information
- physics Isaac physics question
- Support
- Maths yr2 trig help
- Derivation of T = 2π√(l/g)
- Can someone confirm if this question is written incorrectly?
- edexcel ias chemistry p2
- Topics list for Paper 4 OCR maths gcse
- Physics Help
- aqa a level physics mechanics
- Maths A level - Trignometric proof
- Trigonometry
- Trigonometry
- Is anyone studying Construction Project Management at Sheffield Hallam?
- Pre Uni gap year advice
- maths help
- Trigonometry
Latest
Trending
Last reply 19 minutes ago
Based on 2023 GCSEs, will grade boundaries be higher or lower in 2024?GCSEs
16
Last reply 7 hours ago
went from 3s to 9s with (literally) night before revision - ask me anythingGCSEs
57
Trending
Last reply 19 minutes ago
Based on 2023 GCSEs, will grade boundaries be higher or lower in 2024?GCSEs
16
Last reply 7 hours ago
went from 3s to 9s with (literally) night before revision - ask me anythingGCSEs
57
