Question

The perimeter of the rectangle whose length is 60 cm and a diagonal is 61 cm is
A) 120cm
B) 122cm
C)71cm
D) 142cm
​

Answer 1

Answer:

d)142 cm

Step-by-step explanation:

L=60cm

D=61cm

As we know Pythagoras theorem

P²+b²=h²

=>l²+B²=D²

=>60²+b²=61²

=>3600+b²=3721

=>B²=3721-3600

=>b²=√121

=>b=11

P=2(l+b)

=>P=2(60+11)cm

=>P=2*71 cm

=>P=142 cm

Mark as brainliest answer.

Answer 2

Answer:

D) 142cm.

Step-by-step explanation:

Let ΔBCD be the given rectangle such that

AB = CD = 60 cm and AC = 61 cm.

In ΔABC, (AC)2 = (AB)2 + (BC)2 ⇒ (61)2

= (60)2 + (BC)2 ⇒ (BC)2 = 3721 – 3600

= 121 = 112 ⇒ BC = 11 cm

∴ Perimeter of rectangle ABCD = 2(AB + BC) = 2 (60 + 11) = 2(71) = 142

hope it helps =D