Question

the diffrence of two angles of a triangle is 39.8° the sum of the same angles equals 89.2° find the measure of all angles of this triangle​

Answer 1

Let angle 1 be x

Let angle 2 be y

As per given condition

x - y = 39.8 ( 1 )

x + y = 89.2 ( 2 )

Add ( 1 ) & ( 2 )

x - y = 39.8

x + y = 89.2

--------------------

2x = 129

x = 129 / 2

x = 64.5

Substitute value of x in 2

x + y = 89.2

64.5 + y = 89.2

y = 89.2 - 64.5

y = 24.7

angle 1 + angle 2 + angle 3 = 180

( Reason? Sum of all angles of triangle is 180 )

x + y + angle 3 = 180

64.5 + 24.7 + angle 3 = 180

89.2 + angle 3 = 180

angle 3 = 180- 89.2

angle 3 = 90.8

Hope it helps you