Answer:
see explanation
Step-by-step explanation:
Since AC = BC then ΔABC is isosceles with base angles
∠BAC =∠ABC, thus
3x + x = 70
4x = 70 ( divide both sides by 4 )
x = 17.5
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∠ADC is an external angle of ΔABD and the external angle is equal to the 2 opposite interior angles, hence
y = 70 + x = 70 + 17.5 = 87.5
