Question

Rounded to the nearest tenth, what is the perimeter of rectangle ABCD?

A.
48.3 cm
B.
54.6 cm
C.
60.0 cm
D.
173.2 cm

Answer 1

• Answer:

54.6 cm

• Explanation:

Hi there !

T30° => AD = AC/2 = 20cm/2 = 10 cm

T.Phytagoras

CD = √AC² - AD²

= √20² - 10²

= √400-100

= √300

= 10√3

= 10×1.73

= 17.3 cm

P = 2AD + 2CD

= 2×10cm + 2×17.3cm

= 20cm + 34.6cm

= 54.6 cm

Good luck !