The perimeter of a triangle is 6p2−4p+9 and the length of two of its adjacent side are p2−2p+1 and 3p2−5p+3. Find the length if the third side of the triangle. If p = 3, find the perimeter of the triangle. [4 MARKS]
Forming the equation: 1 Mark
Steps: 1 Marks
Equation for perimeter: 1 Mark
Perimeter: 1 Mark
Perimeter of the triangle = sum of the sides of the triangle
6p2−4p+9=p2−2p+1+3p2−5p+3+3rd side
3rd side=6p2−4p+9−[(p2−2p+1)+(3p2−5p+3)]
3rd side=6p2−4p+9−(4p2−7p+4)
3rd side=2p2+3p+5
The 3rd side of the triangle has length is 2p2+3p+5
Given that
p = 3
The perimeter of the triangle is 6p2−4p+9 .
On substituting the values we get:
=6×32−4×3+9
=54−12+9
=51
The perimeter of the triangle is 51 units.