Steps:
(n-2) * 180 = sum of interior angles
(3-2) * 180 = 180
Bottom Triangle
25 + 51 + x = 180
x = 104
Top Triangle
104 + 34 + x = 180
x = 42
Answer:
42
Let the width be x
width = x
length = 2x - 3
Perimeter = x + 2x - 3 + x + 2x - 3 = 6x - 6
6x - 6 = 78
6x = 78 + 6
6x = 84
x = 14 cm
2x - 3 = 2(14) - 3 = 25cm
The width is 14cm and the length is 25cm
You never showed the triangle
Step-by-step explanation:

Answer:
95.1CM²
Step-by-step explanation:
THERE ARE 3 SHAPES
-AREA OF RECTANGLE=LXB
=21 X 3 = 63 CM²
-AREA OF SQUARE = SXS
=5 X 5= 25CM²
-AREA OF CIRCLE = Pi x r²
RADIUS = HALF OF DIAMETER = 1.5
=3.14 X 1.5 ²
=3.14 X 2.25
=7.065
TOTAL AREA= 63 + 25 + 7.065=
ROUNDED = OPTION B
=95.1 CM²
HOPE YOU LIKE THE ANSWER,THX