The area of a triangle is 1/2*base*height so for ABC we need to find the height first. To do this we use pythag theorem, and create the equation 13^2=5^2+height^2 rearranging this we can figure out that sqrt(height)=13^2-5^2. For the base we do 2*5 since there are two congruent line segments both equal to 5. Using this we can do 1/2*12*10=area of ABC
For XYZ we can do 1/2*30*36=area of XYZ, we can do 2*15 since there are 2 congruent 15 length line segments at the base.