How to show that ABC is a right triangle

show that ABC is a right triangle

How to show that ABC is a right triangle

The perimeter of Triangle ABC is 20 cm. AB = 7 cm. BC = 4 cm. Determine whether triangle ABC is a right-angled triangle.

We know the perimeter of the triangle is 20cm, and we also know the lengths of two of the triangle's sides, AB = 7cm and BC = 4cm. By subtracting the known lengths from the perimeter, we can calculate the length of the third side (AC): 20 - 7 - 4 = 9 As a result, the length of AC is 9. If ABC were a right angle triangle, we could apply Pythagoras' Theorem to get the length of AC. Because it is the longest length, AC is the hypotenuse of the triangle. The Theorem of Pythagoras: a2 + b2 = c242 + 72 = 16 + 49 = 65 In the case where AC = c, c2 = 65 When c = 9, c2 = 81; nevertheless, when Pythagoras is used, c2 = 65. As a result, Pythagoras' Theorem is invalid, and the triangle ABC is not a right-angle triangle.


Shahid Lakha
Shahid Lakha

Shahid Lakha is a seasoned educational consultant with a rich history in the independent education sector and EdTech. With a solid background in Physics, Shahid has cultivated a career that spans tutoring, consulting, and entrepreneurship. As an Educational Consultant at Spires Online Tutoring since October 2016, he has been instrumental in fostering educational excellence in the online tutoring space. Shahid is also the founder and director of Specialist Science Tutors, a tutoring agency based in West London, where he has successfully managed various facets of the business, including marketing, web design, and client relationships. His dedication to education is further evidenced by his role as a self-employed tutor, where he has been teaching Maths, Physics, and Engineering to students up to university level since September 2011. Shahid holds a Master of Science in Photon Science from the University of Manchester and a Bachelor of Science in Physics from the University of Bath.