Question

Help!! Geometry Find angle R please!

Answer 1

Hey there!!

Closely observe the triangle, the triangle given is a isosceles triangle , hence, the angles on the base would be equal and hence, angle R = 3x + 30

The sum of all angles in a triangle = 180

Hence , angle R + angle S + angle T = 180

... 3x + 30 + 12x - 15 + 3x + 30 = 180

... 18x + 45 = 180

... 18x = 180 - 45

... 18x =  135

... x = 135 / 18

... x = 7.5

Now substitute the value of x in the angle formula of R and we get the angle R.

... 3x + 30

... 3 ( 7.5 ) + 30

... 22.5 + 30

... 52.5° is the answer

Hope my answer helps!