Mathematics for IGCSE & O level - Proportion (Section 1 - No. 2)
The area of a triangle varies jointly with its base (*b*) and height (*h*). If the area is 10 when b=4 and h=5, what is the area when b=6 and h=3?
9
18
27
36
คำอธิบาย
A=kbh, 10=k*4*5. k=1/2. Therefore A=0.5*6*3=9.