Advertisements
Advertisements
Question
In the right-angled ∆LMN, ∠M = 90°. If l(LM) = 12 cm and l(LN) = 20 cm, find the length of seg MN.
Advertisements
Solution

In the right-angled triangle LMN, ∠M = 90°. Hence, side LN is the hypotenuse.
According to Pythagoras' theorem,
l(LN)2 = l(MN)2 + l(LM)2
⇒ (20)2 = l(MN)2 + (12)2
⇒ 400 = l(MN)2 + 144
⇒ l(MN)2 = 400 − 144
⇒ l(MN)2 = 256
⇒ l(MN)2 = (16)2
⇒ l(MN) = 16
∴ Length of seg MN = 16 cm.
RELATED QUESTIONS
ABC is a right triangle right-angled at C. Let BC = a, CA = b, AB = c and let p be the length of perpendicular from C on AB, prove that
(i) cp = ab
`(ii) 1/p^2=1/a^2+1/b^2`
In Figure ABD is a triangle right angled at A and AC ⊥ BD. Show that AC2 = BC × DC

In the given figure, AD is a median of a triangle ABC and AM ⊥ BC. Prove that:

`"AC"^2 = "AD"^2 + "BC"."DM" + (("BC")/2)^2`
Which of the following can be the sides of a right triangle?
1.5 cm, 2 cm, 2.5 cm
In the case of right-angled triangles, identify the right angles.
For finding AB and BC with the help of information given in the figure, complete following activity.
AB = BC .......... 
∴ ∠BAC = 
∴ AB = BC =
× AC
=
× `sqrt8`
=
× `2sqrt2`
= 

AD is drawn perpendicular to base BC of an equilateral triangle ABC. Given BC = 10 cm, find the length of AD, correct to 1 place of decimal.
In the following figure, AD is perpendicular to BC and D divides BC in the ratio 1: 3.
Prove that : 2AC2 = 2AB2 + BC2
In triangle ABC, AB = AC and BD is perpendicular to AC.
Prove that: BD2 − CD2 = 2CD × AD
Use the information given in the figure to find the length AD.

In the figure below, find the value of 'x'.

