Question

The lengths of the sides of a rectangle are 60cm and 91cm. What is the length of a diagonal?

Answer 1

C^2=a^2+b^2

plug in; c^= 60^2+91^2

c^2=11881
find root
answer= 109cm

Answer 2

Let us draw out the rectangle in the question so that we can understand it clearly

In the figure( see attached file) we have got the measures of two adjacent sides. We know that the angles of the rectangle are right angle that is 90°

We can see that ACD forms an right triangle

now according to the pythagorean theorem we know that

$c^{2} =a^{2} +b^{2}$

where c is the hypotenuse of the right triangle

a and b are the two sides of the triangle

Here we are supposed to find the hypotenuse that is AC

now lets plug in the values of a and b

a= AD = 60cm

b= CD = 91 cm

so we have,

$c^{2} = 60^{2} +91^{2}$

$c^{2} = 3600 + 8281$

$c^{2} = 11881$

$c = \sqrt{11881}$

c = 109 cm

Hence the diagonal measure 109cm