Question

if in a triangle abc, the measure angle A-ANGLE B=25 and angleB -angle C=55.what is the measure of all of its angles?

Answer 1

Given A - B = 25

          A = 25 + B  ---- (1)


Given B - C =55

          C = -55 + B   ----- (2)


We know that sum of interior angles of a triangle = 180.


(25 + B) +B + (-55 + B) = 180

25 + B + B - 55 + B = 180

-30 + B = 180

3B = 210

B = 70 degrees.

Substitute B in (1), we get

A = 25 + 70

A = 95 degrees.

Substitute B in (2), we get

C = -55 + 70

C = 15 degrees.


Verification : 

A + B + C = 180

95 + 70 + 15 = 180.

Hence proved.


Hope this helps!