the hypotenuse of a triangle is 6.5cm and its area is 7.5 cm .calculate the lengths of its perpendicular sides
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Answer:
First area of right angled triangle is:
1/2×base(b) ×height(h).
The base and height always refer to the other two sides except the hypotenuse.
So 12 × b × h = 7.5
Multiplying both sides by 2
bh = 15
Now by Pythagoras theorem
6.52 = b2+h2
42.25=(b+h)2−2bh
Substituting bh = 15
42.25=(b+h)2−30
Adding 30 on both sides
72.25=(b+h)2
Rooting both sides
8.5=b+h
Now bh = 15
or b = 15h
Substituting the above value of b in b+h=8.5
15h+h=8.5
15−8.5h+h2=0
15−6h−2.5h+h2=0
On solving h can be either 6 or 2.5
Now b = 15h=2.5cm (for h=6cm) or 6cm (for h=2.5cm)
So b is 2.5 cm and when h is 6 cm
And b is 6 cm when h is 2.5cm
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