A triangle is always half the area of a rectangle with the same height and width. To calculate the area of a triangle, multiply the height by the width (this is also known as the 'base') then ...

The length of rectangle B = 4 cm + 1 cm = 5 cm. Triangle C: first calculate the height of the triangle. Total height of the shape is 10 cm. Subtracting the 4 cm length of the square which the ...