The correct answer is option (a) 70° is the possible measures of A.
Given that, the isoceles triangle's base angles are equal
let angle D be its vertical angle.
With angle E equal to angle F
angle D+ angle E+ angle F=180'
angle D+ 55'+55'=180',
angle D+ 110'=180'
angle D=180'-110'
angle D=70'.
Figure DEF is an isosceles triangle. The measure of A is 55°, while the measure of B is 70°. As there are two possible measures of D, it can be calculated that the base area equal to 426 square units and the height equals 232 square units.
Hence, 70° is the possible measures of A.
To learn more about isosceles triangle visit:
https://brainly.com/question/2456591
#SPJ1