Question

21. One of the angle of a triangle is 78degrees and the other two angles are equal. Find the measure of the equal angles. ​

Answer 1

the measure of all the angles in a triangle is equal to 180 degree

so,

if one of the angle is 78 degree then ,

180° - 78°

=102°.

Now,

let's suppose the measure of one of the other angle be X and the other angle also be X ..as they are equal angles...

(in other words both the angles together will be called as 2x)

Therefore...,

measure of other two equal angles will be,

2X = 102°

X = 102°÷2

X = 51.

so the first angle will be a 51 degree and other angle will also be 51

(please note that the X written in these equations should be in the small letter not in the capital letter it is by mistake written in the capital form so please write it in the small letter form only)

Answer 2

Answer:

51°

Step-by-step explanation:

measure of 3 angles of triangle is 180°

let measure of equal angles be x

78+x+x= 180

78+ 2x= 180

2x= 180-78

2x= 102

x= 102÷2

therefore x= 51°

78+51+51=180