Question

1)find the perimeter of a circle with radius = 21cm

2)find the area and perimeter of akite with lengths 20cm and 14cm

Answer 1

1)

$$Perimeter=2\pi r=2\pi (21cm)=42\pi cm\approx$$

$$\approx131.947cm$$

2)

$$Perimeter=2(20cm+14cm)=68 cm$$

I cannot find the area of a kite because

$$Area=\dfrac{d_1d_2}{2},$$

where $d_1, d_2$ are the diagonals of the kite, but the diagonals are unknown.