Total angles within a triangle add up to 180∘. This means we can find the other angles by taking away from 180∘!
We can also use SOH CAH TOA (e.g. sin(θ)=hypotenuseopposite).
We cross off each side we have from SOH CAH TOA (where O is the opposite, A is the adjacent, and H is the hypotenuse). For example, crossing off A and H.
Only one of them should have two sides crossed off - that’s the formula we use! For example, if we crossed off A and H then we used C: cosine!
When we have the formula, then we can substitute everything in and re-arrange: more on that next session.
Finding Sides
If we have two sides then we can use Pythagoras’ Theorem!
To find the longest side (hypotenuse): c=a2+b2.
To find one of the other sides: a=c2−b2orb=c2−a2.
If you’re curious, you can prove this quite easily with actual squares - maybe watch a video on it :)
We can use SOH CAH TOA for this, too.
Just follow the same steps as before, but also cross off S, C, and T (since we should have an angle, too!).
Then, choose which function to use (sine, cosine, or the tan one), substitute and solve! Again, more on this next session.
Finding Area
Super easy, just pretend it’s a square and half it! So, half the base times height: A=21bh.