Question

3. The three angles in a trianglealways add up to 180°. If one anglein a triangle is 72° and thesecond is 3 times the third, whatare the three angles?

Answer 1

Given,

The sum of three angles in a triangle is equal to 180°

Let first angle be 72°

Second angle is three times the third

Let third angle be ‘x’

Let second angle be ‘3x’

Now,

Sum of all angles,

=> 72° + x + 3x = 180°

=> 4x + 72 = 180°

=> 4x = 180 -72

=> 4x = 108

=> x =
`(108)/(4)`

=> x = 27°

Now ,

First angle = 72°
Second angle , 3x = 3(27) = 81°
Third angle , x = 27°

Answer 2

First angle = 72°

Second angle = 81°

Third angle = 27°

Step-by-step explanation

The sum of angles in a triangle is 180°

First angle = 72°

Second angle = 3 (Third angle)

Third angle = x = ?

This means the Second angle = 3 (Third angle) = 3x

(First angle) + (Second angle) + (Third angle) = 180°

72° + 3x + x = 180°

72° + 4x = 180°

4x = 180° - 72°

4x = 108°

Divide both sides by 4

(4x/4) = (108°/4)

x = 27°

First angle = 72°

Second angle = 3x = 3 (27°) = 81°

Third angle = x = 27°

Hope this Helps!!!