Find the area of yellow shaded region in which AC = 33 cm, BC = 24 cm, AD =
12 cm and BD = 5 cm and ADB = 90
0 ∠ .(Take √35 = 5.91)
See I have post the pic.
Now please answer this question
Answers
I have attached the given diagram.
We are given the following sides of the triangle,
- AC = 33 cm
- BC = 24 cm
- AD = 12 cm
- BD = 5 cm
- ∠ADB = 90°
Also, we have to take √35 = 5.91
Now, We have to find the area of the yellow coloured shape. Clearly it can be found by subtracting the area of ∆ADB from the area of ∆ABC.
But we need the third side of ∆ABC, i.e., AB which can be found using the Pythagoras theorem in ∆ADB,
In ∆ADB,
using Pythagoras theorem,
⇒ Hypotenuse² = Base² + Perpendicular²
⇒ AB² = BD² + AD²
⇒ AB² = 5² + 12²
⇒ AB² = 25 + 144
⇒ AB² = 169
⇒ AB = 13
Now, In ∆ABC using heron's formula, we have
- a = AB = 13 cm
- b = BC = 24 cm
- c = AC = 33 cm
Also,
- Semi-perimeter, s = (a + b + c)/2 = 35 cm
Now,
⇒ ar(∆ABC) = √{ s(s - a)(s - b)(s - c) }
⇒ ar(∆ABC) = √{ 35(35 - 13)(35 - 24)(35 - 33) }
⇒ ar(∆ABC) = √( 35 × 22 × 11 × 2 )
⇒ ar(∆ABC) = 22√35
⇒ ar(∆ABC) = 130.02 cm²
Similarly, In ∆ADB, Since it is a right angled triangle , so
⇒ ar(∆ADB) = 1/2 × base × height
⇒ ar(∆ADB) = 1/2 × BD × AD
⇒ ar(∆ADB) = 1/2 × 5 × 12
⇒ ar(∆ADB) = 5 × 6
⇒ ar(∆ADB) = 30 cm²
So, Area of shaded region (yellow coloured region)
⇒ ar(∆ABC) - ar(∆ADB)
⇒ 130.02 - 30
⇒ 100.02 cm²
Hence,
Area of yellow shaded region is 100.02 cm²
Two semicircles are drawn with AB and BC as their diameters respectively. Find the shaded area. ... Get Instant Solutions, 24x7. No