Answer:
A = 60°
Step-by-step explanation:
First to find the missing angle you add the three known angles,
90 + 135 + 75 = 300
Then, you subtract, 360 - 300 = 60
<h3>So, 360° = 60° + 90° + 135° + 75°</h3><h3 />
Solve for r.
You want to get r by itself on one side on the equal sign.
bh + hr = 25
Subtract bh from both sides.
hr = 25 - bh
Divide h on both sides.
r = 25 - bh / h
The two h's cancel each other out.
r = 25 - b
Hope this helps!
The answer is parallelograms :-)
17. Area of triangle: 1/2bh
1/2 * 12 * 15
1/2 * 180
=90 cm^2
18. Area of trapezoid: 1/2 h (b1 + b2)
1/2 * 8 ( 12 + 15.4)
4 * 27.4
= 109.6 cm^2
