Answer:
a) Similar triangles are triangles with the same shape but not necessarily the same size
b) 15/45 = 8/x
1/3 = 8/x (simplify the 15/45)
x = 8 * 3 (cross multiplication)
x = 24
c) y^2 = 15^2 + 8^2 (Pythagoras theorem)
y = *square root of* 15^2 + 8^2
y = 17
1/3 = 17/z
z = 17 * 3 (cross multiplication)
z = 51