Question

Triangle ABC has perimeter 22 cm.

AB = 8 cm
BC = 5 cm
By calculation, deduce whether triangle ABC is a right-angled triangle.

Answer 1

No, it isn't a right triangle

Explanation:

AB+ BC + AC= 22 parts whole postulate

8 + 5 + AC = 22 substitution

AC= 22- 13= 9 Algebra

by judging the sides of triangle, we can tell that AC is the longest side therefore is would be the hypotenuse

AC= c

AB= a

CB = b

a^2 + b^2 = c^2 pythagorean theorem

8^2 + 5^2 = 9^2 substitution

64 + 25 = 81 Algebra

89 = 81

ABC is NOT a right triangle

I hope this helps!!!

Answer 2

Answer: yes it is a right angle triangle

Explanation:

a^2 + b^2 = c^2

8^2+ 5^2 = ?

64 + 25 = square root of 89

square root of 89 = 9.4

when we round 9.4 it is 9

so

22- (8+5) =

22 - 13 = 9

so our answer is correct