Advertisements
Advertisements
Question
Find the length of the hypotenuse of a right angled triangle if remaining sides are 9 cm and 12 cm.
Advertisements
Solution

Let ∆PQR be the given right-angled triangle.
In ∆PQR, ∠Q = 90°
∴ PR2 = PQ2 + QR2 .......[Pythagoras theorem]
∴ PR2 = 92 + 122
∴ PR2 = 81 + 144
∴ PR2 = 225
∴ PR = `sqrt(225)` .....[Taking the square root of both sides]
∴ PR = 15 cm
∴ The length of the hypotenuse of the right-angled triangle is 15 cm.
RELATED QUESTIONS
In figure, ∠B of ∆ABC is an acute angle and AD ⊥ BC, prove that AC2 = AB2 + BC2 – 2BC × BD
P and Q are the mid-points of the sides CA and CB respectively of a ∆ABC, right angled at C. Prove that:
`(i) 4AQ^2 = 4AC^2 + BC^2`
`(ii) 4BP^2 = 4BC^2 + AC^2`
`(iii) (4AQ^2 + BP^2 ) = 5AB^2`
A ladder 10 m long reaches a window 8 m above the ground. Find the distance of the foot of the ladder from base of the wall.
A 15 m long ladder reached a window 12 m high from the ground on placing it against a wall at a distance a. Find the distance of the foot of the ladder from the wall.

The diagonals of a rhombus measure 16 cm and 30 cm. Find its perimeter.
Find the side and perimeter of a square whose diagonal is 10 cm.
In the given figure, AB//CD, AB = 7 cm, BD = 25 cm and CD = 17 cm;
find the length of side BC.
In equilateral Δ ABC, AD ⊥ BC and BC = x cm. Find, in terms of x, the length of AD.
In the following figure, OP, OQ, and OR are drawn perpendiculars to the sides BC, CA and AB respectively of triangle ABC.
Prove that: AR2 + BP2 + CQ2 = AQ2 + CP2 + BR2

In Fig. 3, ∠ACB = 90° and CD ⊥ AB, prove that CD2 = BD x AD.

In the given figure, BL and CM are medians of a ∆ABC right-angled at A. Prove that 4 (BL2 + CM2) = 5 BC2.
In triangle PQR, angle Q = 90°, find: PR, if PQ = 8 cm and QR = 6 cm
Find the Pythagorean triplet from among the following set of numbers.
4, 5, 6
The sides of the triangle are given below. Find out which one is the right-angled triangle?
11, 12, 15
In a triangle ABC, AC > AB, D is the midpoint BC, and AE ⊥ BC. Prove that: AB2 + AC2 = 2AD2 + `(1)/(2)"BC"^2`
AD is perpendicular to the side BC of an equilateral ΔABC. Prove that 4AD2 = 3AB2.
Find the length of the support cable required to support the tower with the floor
The perimeter of the rectangle whose length is 60 cm and a diagonal is 61 cm is ______.
In a right-angled triangle ABC, if angle B = 90°, BC = 3 cm and AC = 5 cm, then the length of side AB is ______.
Two squares having same perimeter are congruent.
