8.

Prove that a triangle with the sides a - 1 cm to root under a

vivado [14]

Question is Incomplete, Complete question is given below.

Prove that a triangle with the sides (a − 1) cm, 2√a cm and (a + 1) cm is a right angled triangle.

Answer:

∆ABC is right angled triangle with right angle at B.

Step-by-step explanation:

Given : Triangle having sides (a - 1) cm, 2√a and (a + 1) cm.

We need to prove that triangle is the right angled triangle.

Let the triangle be denoted by Δ ABC with side as;

AB = (a - 1) cm

BC = (2√ a) cm

CA = (a + 1) cm

Hence,

${AB}^2 = (a -1)^2$

Now We know that

$(a- b)^2 = a^2+b^2 - 2ab$

So;

${AB}^2= a^2 + 1^2 -2\times a \times1$

${AB}^2 = a^2 + 1 -2a$

Now;

${BC}^2 = (2\sqrt{a})^2= 4a$

Also;

${CA}^2 = (a + 1)^2$

Now We know that

$(a+ b)^2 = a^2+b^2 + 2ab$

${CA}^2= a^2 + 1^2 +2\times a \times1$

${CA}^2 = a^2 + 1 +2a$

${CA}^2 = AB^2 + BC^2$

[By Pythagoras theorem]

$a^2 + 1 +2a = a^2 + 1 - 2a + 4a\\\\a^2 + 1 +2a= a^2 + 1 +2a$

Hence, ${CA}^2 = AB^2 + BC^2$

Now In right angled triangle the sum of square of two sides of triangle is equal to square of the third side.

This proves that ∆ABC is right angled triangle with right angle at B.

4 0

3 years ago

Show all work:

DerKrebs [107]

Answer:

m=-3

Step-by-step explanation:

m - 7 = -10

Ok so,

in order to get m by itself you just need to do the opposite of -7 which is +7 so you have to add 7 to both sides. On the left, both of the 7's cancel out and on the right -10 + 7 = -3. So, now it should look like this.

m=-3

To check you just need to plug in -3 into the question

Hope this helps! Have a good day

4 0

2 years ago

A _______ is a type of folk song that tells a story.

ElenaW [278]

I Belive it might be ballad

7 0

3 years ago

Read 2 more answers

The lengths of the sides of the triangle are 3, 8, and 10. Is the triangle a right triangle, acute triangle, or an obtuse triang

weqwewe [10]

Answer:

Obtuse

Step-by-step explanation:

You have to make sure it is a triangle by adding the smallest and the medium sides, if the result is greater than the bigger side then it is a triangle.
you then use the Pythagorean theorem to check if the triangle is a right triangle, acute, or obtuse. If $c^{2}$ = $a^{2} +b^{2}$ then it is a right triangle. If $c^{2} >a^{2} + b^{2}$ then it is an obtuse triangle. if $c^{2} < a^{2} +b^{2}$ then it is an acute triangle.