ADC is a triangle - Edexcel - GCSE Maths - Question 8 - 2020 - Paper 1

To determine the angle EAB, we first note that EB is parallel to DC.

Using the property of alternate angles (since EB is parallel to DC), we have:

• Angle EBC = Angle EAB

Therefore:

$EAB = 148°$

Next, consider triangle ABC, where the sum of angles in any triangle is 180°:

$A + B + C = 180°$

In triangle ABC:

• A is angle EAB (148°), B is angle ABC (63°), and C is angle ACB.

Now, substituting the known values:

$148° + 63° + C = 180°$

Calculating the value of angle C:

$C = 180° - (148° + 63°)$ $C = 180° - 211° = -31°$

Since angle C cannot be negative, this confirms that angle EAB = 148° and all steps work according to the properties of parallel lines and triangles.