Question

Help me on number.4 please

Answer 1

I can do it using trigonometry.

Draw a line from O to the point where the circle touches the base line. This will be at right angles to EF and will have length 40. Then draw a line from A parallel to the base to meet OG at H.

consider triangle OAH:-

side OH = 40-25 = 15 cm

cos < AOH = 15/40 giving m < AOH = 67.976 degrees

So m < AOB = 67.976 * 2 = 135.95 degrees

in radians this is 2.37 radians (answer)

Part B:-