11)isosceles triangle -> the diagonals have equal lengths
BP=PC
so it is also 4
12)
DC is longer than AD
The length of the sides is relative to the angles ABD and DBC
obviously the DBC 90° angle is larger than the ABD angle, if ABD would be bigger than 90° and therefore result in the longer side length then ABC wouldn't be a valid triangle, because the inner angle sum would be >180°
13) the trinagles are mirror images of each other, so they have the same side lengths
->
5x-8=2x+13
3x=21
x=7
14) the triangles are similar (same angles, different sizes)
We aren't given the scale factor, so we have to base it on the diagram which looks like the second triangle is 2 times the size of the first
so 2*(3x)=5x+12
6x=5x+12
x=12
