So the formula for the area of a trapezium is area = (a + b)/2 * h *a is the short side * b is the long side *h is the height so let's plug in the values we already know: area, long base, short base. Here's how the formula looks now... 6550 = (150 + 85)/2 * h *so, we need to find 'h' use algebra to find it. 6550 = (235/2) * h 6550 = 117.5 * h 6550/117.5 = h h = 55.74 (approx)
To work out who the unknowns in the room are, we can establish that c = p+ 9
c + p = 25. The unknowns in the room are there the total number of
parents in the room, and the total number of teachers in the room.
