Triangle ABC is isosceles with AB = BC. If AC = 20 and [ABC] = 280, then find the perimeter of triangle ABC.

Guest Jan 11, 2021

#1**+1 **

I found another person who asked the same question and someone answered it: https://web2.0calc.com/questions/triangle-abc-is-isosceles-with-ab-bc-if-ac-20-and

Potatobird Jan 11, 2021

#2**0 **

My solution: Draw the altitude BP. Then PA = PC = 10. So, we have that 20*BP/2 = 280, so BP = 28. As we have that 10^2+28^2 = 884, the perimeter of ABC is 4√221 + 20.

Pangolin14 Jan 11, 2021