In the diagram below, $O$ is the centre of the circle with radius $4$ cm and passing through the

Question

In the diagram below, $O$ is the centre of the circle with radius $4$ cm and passing through the points $A$, $B$, $C$ and $D$. $E$ is the midpoint of $OC$. $AOEC$ is a straight line. $A$ is the centre of a circle through $B$, $E$ and $D$. Show that $\angle AOB$ is approximately $1.70$ rad. Calculate the area of sector $OBCD$, the perimeter of the shaded region, the area of the shaded region.

Accepted Answer

(a) $1.70$ rad (shown) (b)(i) $23.1\text{ cm}^2$ (b)(ii) $20.2$ cm (b)(iii) $13.0\text{ cm}^2$

IP2U13 13.4 PN1 Q10

IP2U13 13.4 PN1 Q10

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