In a square ABCD, the diagonals bisect at O. What type of a triangle i...
Solution:Given: In a square ABCD, the diagonals bisect at O.
To find: What type of a triangle is AOB?
Explanation:Let's draw the square ABCD and its diagonals as shown below:
https://www.edurev.in/api/img/content/d3da2fec9c2e0967d7b6a4f7a6b7e18f.png" />
From the above figure, we can see that:
- AO and BO are radii of the circle with center O.
- Since the diagonals of a square bisect each other, we have:
AO = BO = CO = DO
- Therefore, triangle AOB is an isosceles triangle with AB as the base and AO = BO as the equal sides.
Now, we need to determine if triangle AOB is also a right-angled triangle.
- Let's consider triangle AOD.
- In triangle AOD, we have:
AD = OD (as diagonals bisect each other)
angle AOD = 90 degrees (as diagonal BD is perpendicular to AD)
Therefore, triangle AOD is an isosceles right-angled triangle.
- Since AO = OD, we have:
angle ADO = angle AOD = 45 degrees
- Therefore, angle AOB = 2 x angle ADO = 2 x 45 = 90 degrees.
Hence, we can conclude that triangle AOB is an isosceles right-angled triangle.
Therefore, the correct answer is option (D) - An isosceles right-angled triangle.