Question

In a right angle triangle, the ratio of
two angles other than right angle is 4
:5. Find the smallest angle.
(1 Point)
O 35 degree
O 40 degree
o 45 degree
O 50 degree​

Answer 1

Answer:

Correct option is

B

40 : 50

Let the angles be 4x and 5x

Now their sum is 90

∘

4x+5x=90

∘

⇒9x=90

∘

⇒x=10

∘

So the angles are

4×10

∘

=40

∘

5×10

∘

=50

∘

Answer 2

Proper question: In a right angle triangle, the ratio of two angles other than right angle is 4:5 Find the smallest angle.

Provided that:

→ In a right angle triangle, the ratio of two angles other than right angle is 4:5

To find: The smallest angle

Solution: The smallest angle = 40°

Knowledge required: Right angled triangle is that triangle whole one angle is equal to 90 degree.

Assumptions:

→ Let the common ratio as a

→ Let the ratio of two angles other than right angle is 4:5 as 4a and 5a respectively.

Required solution:

→ 4a + 5a = 90°

→ 9a = 90°

→ a = 90/9

→ a = 10°

→ Therefore, common ratio = 10°

~ Now let us calculate the value of both the given angles that are in ratio!

First angle would be,

→ 4a

→ 4(10)

→ 4 × 10

→ First angle = 40°

Second angle would be,

→ 5a

→ 5(10)

→ 5 × 10

→ Second angle = 50°

Third angle we have,

→ Already 90° as the given triangle is right angled triangle.

• Therefore, 40 < 50 < 90 Henceforth, the smallest angle is 40° Therefore, option (b) is correct! $\:$