For the first picture I drew 2 lines to make quarters on the picture.In the top half 1 triangle is half of the half (to make the fractions easy to understand I changed them into 8ths) which is 2 8ths and as the top triangle is the same as the left hand side triangle you know that the left hand side triangle is also 2 8yhs.In the bottom right hand corner the triangle is half the quarter so the triangle is 1 8th.Then if you add up all the 8ths you get 5 8ths that means that the remaining centre triangle is 3 8ths.
For the second picture I split it into 16ths but I calculated it in to 32ths so I could work out the answer more easily.In the top right hand corner triangle it was half of 2 16ths which (in 32ths) is 2 32ths.That is the same as each corner and the quarters of the big middle shape which means overall the middle shape is 8 32ths.In the centre of the right and left hand side each side's 2 16ths is 1 16th of the 2 16ths.That means that each side triangle is 2 32ths. Then if you add up the triangles you have calculated so far you get 20 32ths so the remaining shapes have 12 32ths all together so each of the remaining triangles is 3 32ths.