Answer:
56.4 degrees
Explanation:
You can make a right-angle triangle from the isosceles triangle, with height 2.5cm and hypotenuse 3cm.
You have the opposite side to the angle and the hypotenuse, so you use sin x = Opposite/Hypotenuse
sin x = 2.5/3
x =
(2.5/3)
x = 56.44269024
Therefore the base angle of the triangle is 56.4 degrees (3sf)