Question

the second angle of a triangle is double the first. the third angle is 40less than the first. find the three angles​

Answer 1

Answer:

a = 55°

b = 110°

c = 15°

Step-by-step explanation:

Let First Angle Be a

Let Second Angle Be b

Let Third Angled Be c

Now,

b = 2a

c = a - 40°

& a + b + c = 180°

So,

a + 2a + a - 40° = 180°

4a - 40° = 180°

4a = 180° + 40° = 220°

a = 220°/4 = 55°

b = 2 × 55° = 110°

c = 55° - 40° = 15°

Hope It Helps!

Answer 2

Answer:

Let, the first angle be x°

Second angle = 2x°

Third angle = (x - 40)°

Now, first angle + second angle + third angle = 180°  

(angle-sum property of triangles)

= x + 2x + (x - 40) = 180°

= 4x - 40 = 180°

= 4x = 220°

x = 55°

2x = 110°

(x - 40) = 15°

Therefore,

The first angle =  55°

The second angle = 110°

The third angle = 15°

Hope it helps you :)