Question

In triangle abc ,angle a=40° and angle b=60° . find the longest side of the triangle abc

Answer 1

The third angle (angle c) = 80° [ Angle sum property ]

The side opposite to the longest angle is the longest side.

∴ AB is the longest side of the triangle.

Answer 2

Answer:

Required value of longest side is 80°

Step-by-step explanation:

Here given triangle is ABC.

angle a$= {40}^{o}$

and angle $= {60}^{o}$

Here we want to find third side of the triangle.

We know,Sum of all angles of a triangle is 180°.

If x,y,z are three angles of triangle then

$x + y + z = {180}^{o}$

For example,

a triangle has three angles are 20°,30°,p

then

${20}^{o} + {30}^{o} + p = {180}^{o} \\ p = {180}^{o} - {20}^{o} - {30}^{o} \\ p = {130}^{o}$

Here given two angles of triangle is 40° and 60°

Let value of angle c be a.

According to rule,

${40}^{o} + {60}^{o} + a = {180}^{o} \\ {100}^{o} + a = {180}^{o} \\ a = {180}^{o} - {100}^{o} \\ a = {80}^{o}$

Required value of angle c is 80°.

Which is the longest side of the triangle.