We know that the area of triangle = 12×base×height
In first row, base = 15 cm and area = 87cm2
∴ 87 = 12×15×height ⇒ height = 87×215 = 11.6 cm
In second row, height = 31.4 mm and area = 1256 mm2
∴ 1256 = 12×base×31.4 ⇒ base = 1256×231.4 = 80 mm
In third row, base = 22 cm and area = 170.5 cm2
∴ 170.5 = 12×22×height
⇒ height = 170.5×222 = 15.5 cm
Thus, the missing values are:
BaseHeightArea of triangle15 cm11.6 cm87 cm280 mm31.4 mm1256 mm222 cm15.5 cm170.5 cm2