Answer:
- 10) x = 76,
- 12) x = 8, Perimeter = 77 units
=========================
Question 10
The triangle is isosceles as marked.
The two opposite angles of equal sides are equal, one of them is x and the angle in between them is 28°.
Use angle sum of the triangle:
- 2x + 28 = 180
- 2x = 152
- x = 76
Question 12
Same as previous question, we have an isosceles triangle. Equal sides are:
- 3x + 5 = 5x - 11
- 5x - 3x = 5 + 11
- 2x = 16
- x = 8
Find the perimeter by substituting the value of x:
- P = 3*8 + 5 + 5*8 - 11 + 2*8 + 3 = 77 units