Question

one angle of a triangle is 30 degree and the second angle is thrice that of third angle find the measure of all angles

Answer 1

let the third angle be x , 2nd angle be 3x and 1st angle=30°

then
x+3x+30=180°
4x=180°-30°
x=150°/4
x=37.5°

so the three angles of triangle would be

=30°

=37.5°

=3x=3×37.5
=112.5°

verifying our answer:-

=30°+37.5°+112.5°
=180°

Answer 2

Answer:

Step-by-step explanation:

let the angles of triangle be ∠a,∠b,∠c

one angle of a triangle is (a) 30°..........(1)

by the given condition

the second angle is thrice that of third angle

∴ ∠b = 3∠c...............(2)

by the addition law of angles

∠a+∠b+∠c = 180°

∴  30°+3c+c = 180°

∴  4c = 180-30

∴  4c = 150

∴   c = 150/4

∴   ∠c = 37.5°

∴  ∠b = 3c   .............. ( by eq 2)

∴   ∠b = 3*37.5

∴   ∠b = 112.5°