Question

The perimeter of a triangle is 14a2? + 20a + 13. Two of its sides are 3a? + 5a + 1
and a? + 10a - 6. Find its third side.​

Answer 1

Answer:

As we know that the perimeter of a triangle is the sum of all the sides.

Suppose that the third side of the triangle is X then,

According to the given data in the question-

Perimeter of a triangle = 14a2 + 20a + 13

Sum of two sides

= 3a2 + 5a + l + a2 + 10a – 6

= 3a2 + a2 + 5a + 10a + 1 – 6

= 4a2 + 15a – 5

∴ Third side (14a2 + 20a + 13) – (4a2 + 15a – 5)

= 14a2 + 20a + 13 – 4a2 – 15a + 5

= 14a2 – 4a2 + 20a – 15a + 13 + 5

= 10a2 + 5a + 18