Q). The area of a right-angled triangle is 600 cm². If the base of the triangle exceeds the altitude by 10 cm, find all the three dimensions of the triangle.
(Q 33 B – 30/2/1 – CBSE 2026 Question Paper)
Ans:
Step 1: Let’s consider the Alttitude of the triangle is A
By given condition, base of the triangle exceeds the altitude by 10 cm
∴ Base = A + 10
Step 2: In a Right angled triangle, area =
x Base x Altitude
=
x (A + 10) x A
Since it is given that Area of triangle = 600 cm 2
∴
x (A + 10) x A = 600
∴ A (A + 10) = 1200
∴ A 2 + 10 A – 1200 = 0
By mid term splitting, A 2 + 40 A – 30 A – 1200 = 0
∴ A (A + 40) – 30 (A + 40) = 0
∴ (A + 40) (A – 30) = 0
∴ A = – 40 and A = 30
Step 3: Because side can not be negative, hence, we reject A = – 40
and accept A = 30 cm
∴ Altitude = 30 cm
∴ Base = A + 10 = 30 + 10
∴ Base = 40 cm
Step 4: In a right angled triangle,
Hypotenuse = ![]()
= √ 2500 = 50 cm.
Therefore, the dimensions of the triangle are 30 cm, 40 cm, 50 cm.
Check: We have altitude as 30 cm and base is 40 cm,
∴ Base exceeds the altitude by 10 cm …..it meets 1st condition
Area of triangle = (1/2) x 30 x 40 = 600 cm 2
∴ It meets 2nd condition too.
∵ both conditions are satisfied ∴ our answer is correct.
Please press the “Heart” button if you like the solution.
