Answer:
The lateral surface area of a cuboid is 180 units² .
Option (c) is correct.
Step-by-step explanation:
Formula
Lateral surface area of a cuboid = 2hl + 2hb
Where h is the height , l is the length and b is the breadth.
As shown in the figure.
Length = 4 units
Breadth = 5 units
Height = 10 units
Put in the formula
Lateral surface area of a box = 2 × 10 × 4 + 2 × 10 × 5
= 80 + 100
= 180 units ²
Therefore the lateral area of the cuboid is 180 units² .
Option (c) is correct.
Answer:
13 is reflection over the X axis
Step-by-step explanation:
Answer:
1
Step-by-step explanation:
extending answer to be able to send

by using the integration formula
we get,

now put the value of t=\sin\theta in the above equation
we get,

hence proved
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,
Now We know that

So;


Now;

Also;

Now We know that




[By Pythagoras theorem]

Hence, 
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.