Answer:
Base = 24 cm or 10cm
Step-by-step explanation:
REMEMBER:
An isosceles triangle ABC with base BC = ‘b' & height AD = ‘h' & its equal sides =13 cm & area = 60 cm²
Using the formulas


There are 2 solutions for 
≈ 
Less complex:
Area of a triangle = 1/2 * b * h = 60
=> h = 120/b
In right triangle ABD
13² = h² + b² /4 ( by Pythagoras law)
=>169 = 120²/b² + b²/4
=>676 b² = 57600 + b^4
=> b^4 - 676 b² + 57600 = 0
=> b² = 676 +- √(676² - 4*57600) / 2
=> b²= 676 +- √(226576) /2
=> b² = (676 +- 476 )/2
=> b² = 1152/2 , 200 /2
=> b² = 576 , 100
=> b = 24, 10
So, Base = 24 cm or 10cm
Answer:
B = 34.2°
C = 58.2° or 121.8°
c= 10.6
Step-by-step explanation:
Step 1
Finding c
We calculate c using Pythagoras Theorem
c²= a² + b²
c = √a² + b²
a= 8, b = 7
c = √8² + 7²
c = √64 + 49
c = √(113)
c = 10.630145813
Approximately c = 10.6
Step 2
Find B
We solve this using Sine rule
a/sin A = b/sin B
A = 40°
a = 8
b = 7
Hence,
8/sin 40° = 7/sin B
8 × sin B = sin 40° × 7
sin B = sin 40° × 7/8
B = arc sin (sin 40° × 7/8)
B ≈34.22465°
Approximately = 34.2°
Step 3
We find C
Find B
We solve this using Sine rule
b/sin B = c/sin C
B = 34.2°
b = 7
c = 10.6
C = ?
Hence,
7/sin 34.2° = 10.6/sin C
7 × sin C = sin 34.2 × 10.6
sin C = sin 34.2° × 10.6/7
C = arc sin (sin 34.2° × 10.6/7)
C = arcsin(0.85)
C= 58.211669383
Approximately C = 58.2°
Or = 180 - 58.2
C = 121.8°
1.)
-x=3-4x+6
3x=3+6
3x=9
X=3
c
2.)
-6+x=-2
x=4
B
The reflection point P' would be (-6, 8)