Question

base of right angle triangle is 12cm and its hypotenuse is 13 cm long. find area and perimeter

Answer 1

the other side of the triangle is (13^2-12^2)^.5=5
thus area=1/2×base×height=1/2×12×5=30cm^2
and perimeter=12+13+5=30cm

Answer 2

It is given that

ABC is a right angled triangle

BC = 12 cm and AB = 13 cm

Using the Pythagoras theorem

AB2 = AC2 + BC2

Substituting the values

132 = AC2 + 122

By further calculation

AC2 = 132 – 122

So we get

AC2 = 169 – 144 = 25

AC = √25 = 5 cm

We know that

Area of triangle ABC = ½ × base × height

Substituting the values

= ½ × 12 × 5

= 30 cm2

Similarly

Perimeter of triangle ABC = AB + BC + CA

Substituting the values

= 13 + 12 + 5

= 30 cm