AQA · Mathematics · 8300
GCSE Maths: Trigonometry: area of a triangle
Geometry & Measures · AQA GCSE Maths (8300). Cards are generated from the Corbettmaths textbook exercise and practice questions for Trigonometry: area of a triangle (Corbettmaths Video 337), and every card links back to the exact page it came from. Practice tests generate fresh variations of these questions, so the numbers change every attempt. Source material © Corbettmaths — used with attribution.
8 flashcards · Free to study · No account needed
Study this deck
Preparing your cards…
All questions and answers
Read through the full deck, or practise recalling each answer above.
The formula for the area of a triangle using trigonometry is A = ½ab?
Show answer
SinC
In the formula A = ½abSinC for the area of a triangle, what does 'C' represent?
Show answer
The angle between sides a and b.
What triangle measurements do you need to use the formula A = ½abSinC?
Show answer
Two sides and the included angle (the angle between those two sides).
If triangle ABC has AB = 10cm, BC = 9cm and angle ABC = 44°, which formula would you use to find its area?
Show answer
A = ½abSinC, specifically A = ½ × 10 × 9 × Sin(44°). You have two sides and the included angle.
Why can't you use the formula A = ½ × base × height when you only know two sides and an angle of a triangle?
Show answer
Because you don't know the perpendicular height. The formula A = ½abSinC solves this by using the angle instead.
How can you find the area of a parallelogram using trigonometry if you know two adjacent sides and the included angle?
Show answer
Use A = abSinC (without the ½), or split it into two triangles and use A = ½abSinC for each.
If you know the area of a triangle and two of its sides, what can you find using A = ½abSinC?
Show answer
The included angle C between those two sides. Rearrange to SinC = 2A/(ab), then use inverse sine.
If you know the area of a triangle, one side, and the included angle, what can you find using A = ½abSinC?
Show answer
The other side. Rearrange to b = 2A/(aSinC) or a = 2A/(bSinC).
Want to create your own cards? Create a free account. AI generation uses credits.