Let x and y be islands and peninsulas respectively
x+y=191919
2x+3y=454545
y = 191919- x
2x + 3 (191919 - x) = 454545
2x + 575757 - 3x = 454545
2x-3x = 454545 - 575757
-x = -121212
x = 121212
121212 + y = 191919
y = 191919 - 121212
y = 70707
Ni Hua visited 121212 islands and 70707 peninsulas
Answer:
a. 15/2 or 7.5 sqcm
b. 20 sqcm
Step-by-step explanation:
Area of a triangle is (base × height)/2.
A = (5×3)/2
A = 15/2 = 7.5cm^2
The area of a parallelogram is just base × height, but yoy have to choose wisely what is the base and height. These two measurements must be perpendicular. So the 4 and 5 are perpendicular. We won't use the measurement 6cm at all.
Area = 4×5
Area = 20 sqcm
