In this case, we'll have to carry out several steps to find the solution.
Step 01:
data:
isosceles triangle:
ratio:
4 : 3
Step 02:
geometry:
triangles:
ratio (vertex angle: base angle):
4 : 3
vertex angle = 4x
base angle = 3x
the base angles of an isosceles triangle are equal:
(4x)° + (3x)° + (3x)° = 180°
4x + 3x + 3x = 180
10x = 180
x = 180 / 10
x = 18
vertex angle = 4x = 4(18) = 72°
base angles = 3x = 3(18) = 54°
The answer is:
vertex angle = 72°
base angles = 54°