Two similar triangles have areas 490 cm2 and 640 cm2. If the length of one side of the first triangle is 21 cm, then what is the length of the corresponding side of the second triangle?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 24 cm.
Let the length of the corresponding side of the second triangle = x cm
(21/x)2 = 490/640 = 49/64
⇒ (21/x)2 = (7/8)2
⇒ 21/x = 7/8
⇒ x = 24 cm