Let ABC and PQR be two congruent triangles, such that ∠A = ∠P = 90°. If BC = 29 cm, PR = 21 cm, find the value (in cm) of AB.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1. i.e. 20 cm.
Given that
ABC and PQR are two congruent triangles
∠A = ∠P = 90°
BC = 29 cm, PR = 21 cm,
Two pairs of corresponding sides and the corresponding angles between them are equal.
The corresponding sides of PR = AC = 21cm
In triangle ABC, by Pythagoras theorem
⇒ AB2 + AC2 = BC2
⇒ AB2 + 212 = 292
⇒ AB2 = 841 - 441 = 400
⇒ AB = 20 cm