Question

Triangle ABC has perimeter 22cm

AB = 8cm
BC = 5cm

By calculation, deduce whether triangle ABC is a right-angled triangle

Answer 1

Explanation:

To calculate this we use Pythagoras' theorem: a^2+b^2=c^2

in this case a=8cm, b=5cm and c=22

so we do 8^2+5^2=89

the square root of 89 is 9.4 (1 d.p)

8+5+9.4=22.4 so rounded (22), this triangle is a right-angled triangle since Pythagoras theorem has proved ABC is a right-angled triangle