Question

the perimeter of a triangle is 45, if the largest side is twice the smallest and the medium side is the smallest increased by 5. find all three sides of the triangle.

Answer 1

Let x is the smallest side, then the largest side is 2xand the medium side is x+5. Write the perimeter of the triangle which is the sum of the lengths of its sides
x+2x+x+5=45
Solve this equation
4x=40
x=10
Thus the smallest side of the triangle is 10, the medium side is 10+5=15 and the largest side is 2⋅10=20.