Find the area of a right angle whose base is 15 cm and hypotenuse is 17 cm.
- A40 cm²
- B55 cm²
- C60 cm²
- D75 cm²
Solution & Step-by-step Explanation
For a right-angled triangle, let the base be b=15cm and the hypotenuse be h=17cm. Let the perpendicular (height) be p.
By Pythagoras theorem:
p
2
+b
2
=h
2
p
2
+15
2
=17
2
p
2
+225=289
p
2
=289−225
p
2
=64
p=
64
=8cm
Now, the area of the right-angled triangle is:
Area=
2
1
×base×height
Area=
2
1
×15×8=15×4=60cm
2
By Pythagoras theorem:
p
2
+b
2
=h
2
p
2
+15
2
=17
2
p
2
+225=289
p
2
=289−225
p
2
=64
p=
64
=8cm
Now, the area of the right-angled triangle is:
Area=
2
1
×base×height
Area=
2
1
×15×8=15×4=60cm
2