Answer:
I guess you want to find the lenght of the sides and the other angle, so let's do that:
We know that the base has a length of 14 cm.
The two base angles are 68°
First, we can find the other angle knowing that the sum of all interior angles of a triangle must add up to 180°.
2*68° + X = 180°
X = 180° - 2*68° = 44°
Now let's find the length of the sides (that is the same for both sides, as we have an isosceles triangle.
For this we can draw a line for the middle of the base that goes through the top vertex, creating in this way a triangle rectangle.
We know that one of the cathetus will have half of the length of the base, this is 7cm.
the adjacent angle to this cathetus is 68°, now we want to find the hypotenuse of this triangle, we can use the relation:
Cos(A) = adjacent cathetus/hypotenuse:
Cos(68°) = 7cm/H
H = 7cm/cos(68) = 18.7cm
this hypotenuse is equal to the side length of our isosceles triangle, so now we have it fully determined.