Answer:
X=
Step-by-step explanation:
First you have to divide the shape into to triangles. Triangle CED and triangle ACB.
Second you have to find what angle C is in the triangle ACB. For this you'll have to:
Find out which of the sides are which. For triangle ACB, side CB is the hypotenuse, CA and AB are adjacent.
The formula we use is . a and b are adjacent and c is hypotenuse.
When you found what angle C is, you can go on and to the second triangle same theorem applies to the second triangle . At this stage you will already know two angles, 100 and c, so finding E using this formula will be easy