Question

in figure triangle ABC is right angle at B if AB= 9cm AC = 15cm and D,E are the mid point of AB and AC respectively calculate 1. the length of BC 2. the area of trapezium BCED

Answer 1

Answer:

Step-by-step explanation:

Answer 2

AB = 9cm
AC = 15cm

AC is the hypotenuse in the triangle.

AB is the perpendicular line.

BC is the base in the triangle.

By using Pythagoras theorem.
Hypotenuse = Base^2×Perpendicularline^2
= AC^2 = BC^2 × AB^2
= 15cm^2 = BC^2× 9cm^2
= BC^2 = 15cm^2 - 9cm^2
= BC^2 = 225cm - 81cm
=BC^2 = 144cm
= BC = sq. root of 144cm
= BC = 12cm

DE^2 = AE^2 - AD^2
= DE ^2= 7.5cm^2 - 4.5cm^2
=DE ^2= 56.25cm - 20.25cm
= DE^2 = 36cm
=DE= Sq. root of 36cm
=DE = 6cm

Area of a trapezium = 1/2 ×Height×(base1×base2) ×
1/2×4.5cm×(6+12)cm
= 1/2× 4.5cm×18cm
=1/2×45/10cm×18cm
=9×9/2cm
81/2cm
=40.5cm^2