Question

Find the perimeter of rectangle whose length is 16 cm and diagonal is 20 cm ​

Answer 1

see attachment ABCD is a rectangle

Rectangle triangle ADC

Diagonal AC

pythagoras

AC²=AD²+DC²

20²=AD²+16²

AD²=20²-16²

AD = √144 = 12cm

Perimeter = 2(16+12)= 2*28 = 56cm