Question

A traffic signal plate in the shape of triangle is having base 20 cm, height 15 cm. Find the area of the triangle. If the cost of painting is ₹ 2 per Sq.cm, then find the total cost for painting the signal board on one side.

Answer 1

Given the base of the signal plate b = 20 cm 

Height of the signal plate h = 15 cm 

Area of the signal plate = \(\frac 12\) ∙ b ∙ h

= 150 sq.cm 

∴ Area of the signal plate = 150 sq.cm

Cost of painting per sq.cm = ₹ 2 

Cost of painting for 150 sq.cm = 150 × 2 

∴ Total cost for painting the signal board = ₹ 300