Two angles of a triangle are in the ratio of [tex]$5:4$[/tex], and the third angle is [tex]$90^{\circ}$[/tex]. Find all the angles in degrees.

One angle of a triangle is [tex]$50^{\circ}$[/tex]. If the ratio of the remaining two angles is [tex]$7:8$[/tex], find all the angles.



Answer :

Certainly! Let's break down each part of the question:

### Part 1: Find all angles of the first triangle
We are given that two angles of a triangle are in the ratio [tex]\(5:4\)[/tex] and the third angle is [tex]\(90^\circ\)[/tex].

1. Recall that the sum of all angles in any triangle is [tex]\(180^\circ\)[/tex].

2. Let the two unknown angles be represented as [tex]\(5x\)[/tex] and [tex]\(4x\)[/tex]. The third angle is [tex]\(90^\circ\)[/tex].

3. The sum of all angles in the triangle:
[tex]\[ 5x + 4x + 90^\circ = 180^\circ \][/tex]

4. Combine like terms:
[tex]\[ 9x + 90^\circ = 180^\circ \][/tex]

5. Subtract [tex]\(90^\circ\)[/tex] from both sides:
[tex]\[ 9x = 90^\circ \][/tex]

6. Divide by [tex]\(9\)[/tex]:
[tex]\[ x = 10^\circ \][/tex]

7. Now, calculate the actual angles:
[tex]\[ 5x = 5 \times 10^\circ = 50^\circ \][/tex]
[tex]\[ 4x = 4 \times 10^\circ = 40^\circ \][/tex]

So, the angles of the first triangle are:
[tex]\[ 50^\circ, 40^\circ, 90^\circ \][/tex]

### Part 2: Find all angles of the second triangle
We are given that one angle of a triangle is [tex]\(50^\circ\)[/tex] and the ratio of the remaining two angles is [tex]\(7:8\)[/tex].

1. Recall again that the sum of all angles in a triangle is [tex]\(180^\circ\)[/tex].

2. Let the remaining two angles be represented as [tex]\(7y\)[/tex] and [tex]\(8y\)[/tex]. The given angle is [tex]\(50^\circ\)[/tex].

3. The sum of all angles in the triangle:
[tex]\[ 50^\circ + 7y + 8y = 180^\circ \][/tex]

4. Combine like terms:
[tex]\[ 50^\circ + 15y = 180^\circ \][/tex]

5. Subtract [tex]\(50^\circ\)[/tex] from both sides:
[tex]\[ 15y = 130^\circ \][/tex]

6. Divide by [tex]\(15\)[/tex]:
[tex]\[ y \approx 8.6667^\circ \][/tex]

7. Now, calculate the actual angles:
[tex]\[ 7y = 7 \times 8.6667^\circ \approx 60.6667^\circ \][/tex]
[tex]\[ 8y = 8 \times 8.6667^\circ \approx 69.3333^\circ \][/tex]

So, the angles of the second triangle are:
[tex]\[ 50^\circ, 60.6667^\circ, 69.3333^\circ \][/tex]

In summary, the angles are:
1. For the first triangle: [tex]\(50^\circ, 40^\circ, 90^\circ\)[/tex]
2. For the second triangle: [tex]\(50^\circ, 60.6667^\circ, 69.3333^\circ\)[/tex]