Triangle ABC has perimeter 18 cm. AB = 7 cm
BC = 3 cm
By calculation, deduce whether triangle ABC is a right-angled triangle.

Please be quick,,it’s a test!!

AB= 7cm

BC=3cm

AC= x

Perimeter of triangle = AB + BC + AC

18 cm = 7cm + 3cm + X

18cm = 10cm + X

X = 18cm - 10cm

X = 8cm.

The pythagorean theorem states that in a right triangle a2 + b2 = c2, where c is the length of the hypotenuse (the longest side opposite to the right angle) and a and b are the lengths of the other two sides.

AC^2 = AB^2 + BC^2

8^2 =7^2 + 3^2

64 = 49 + 9

64 = 58

Since the equation is not true, we can deduce that ABC is NOT a right triangle.